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Home/Chain Registry/Block #1,348,649

Block #1,348,649

1CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the First Kind Β· Discovered 11/30/2015, 11:33:30 AM Β· Difficulty 10.8199 Β· 5,492,543 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
8de1fda7a800cf2696553205792fc9a2a2e59d3b5575336dbf4390cfa6ab05fb
View on Chainz β†—

Difficulty

10.819943

Transactions

1

Size

200 B

Version

2

Bits

0ad1e7c1

Nonce

2,081,871,237

Timestamp

11/30/2015, 11:33:30 AM

Confirmations

5,492,543

Merkle Root

1dcb17f8bb664e6b96ba828212ff987b51b426ddf9fd30c7d193062ca43e1d57
Transactions (1)
Coinbase1dcb17f8bb664e…93062ca43e1d57
1 in β†’ 1 out8.5300 XPM110 B
AFyQqxBU…sh9EQAmv
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) β€” it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

9.395 Γ— 10⁹⁡(96-digit number)
93952181507422273047…22162318973792689920
Discovered Prime Numbers
p_k = 2^k Γ— origin βˆ’ 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin βˆ’ 1
9.395 Γ— 10⁹⁡(96-digit number)
93952181507422273047…22162318973792689919
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
2
2^1 Γ— origin βˆ’ 1
1.879 Γ— 10⁹⁢(97-digit number)
18790436301484454609…44324637947585379839
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
3
2^2 Γ— origin βˆ’ 1
3.758 Γ— 10⁹⁢(97-digit number)
37580872602968909219…88649275895170759679
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
4
2^3 Γ— origin βˆ’ 1
7.516 Γ— 10⁹⁢(97-digit number)
75161745205937818438…77298551790341519359
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
5
2^4 Γ— origin βˆ’ 1
1.503 Γ— 10⁹⁷(98-digit number)
15032349041187563687…54597103580683038719
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
6
2^5 Γ— origin βˆ’ 1
3.006 Γ— 10⁹⁷(98-digit number)
30064698082375127375…09194207161366077439
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
7
2^6 Γ— origin βˆ’ 1
6.012 Γ— 10⁹⁷(98-digit number)
60129396164750254750…18388414322732154879
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
8
2^7 Γ— origin βˆ’ 1
1.202 Γ— 10⁹⁸(99-digit number)
12025879232950050950…36776828645464309759
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
9
2^8 Γ— origin βˆ’ 1
2.405 Γ— 10⁹⁸(99-digit number)
24051758465900101900…73553657290928619519
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
10
2^9 Γ— origin βˆ’ 1
4.810 Γ— 10⁹⁸(99-digit number)
48103516931800203800…47107314581857239039
Verify on FactorDB β†—Wolfram Alpha β†—

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Cunningham Chain of the First Kind. The prime chain origin β€” the large number shown above β€” anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

View full Prime Chain Discovery page β†’
β˜…β˜…β˜†β˜†β˜†
Rarity
UncommonChain length 10
How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 Γ— 3 Γ— 5 Γ— 7 Γ— …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial β€” that divisibility is part of the proof.

Prime Chain Origin = First Prime Γ— Primorial (2Β·3Β·5Β·7Β·11·…)
Source: Primecoin prime.cpp β€” CheckPrimeProofOfWork()

This is why the origin has many small prime factors β€” those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), pβ‚‚ = 2p₁ + 1, p₃ = 2pβ‚‚ + 1, …
Verify on a Primecoin Node

Anyone running a Primecoin node can independently verify this block using the following RPC commands. Run these from the primecoin-cli command line or via the debug console in the Primecoin wallet.

1. Get block hash by height
getblockhash 1348649

Returns the block hash for a given block height. Use this to confirm the hash shown above matches the chain.

2. Get full block data
getblock 8de1fda7a800cf2696553205792fc9a2a2e59d3b5575336dbf4390cfa6ab05fb

Returns the full block header including difficulty, prime chain origin, prime chain type, transaction IDs, and all other fields shown on this page.

How to run these commands: To verify this data independently, open a terminal on your own Primecoin node and run primecoin-cli <command>. Alternatively, open the Primecoin-Qt wallet, go to Help β†’ Debug Window β†’ Console, and type the command directly. The node must be fully synced to this block height for the commands to return results.

Cross-reference on Chainz Explorer

Chainz is an independent Primecoin block explorer. Compare this block's data to verify accuracy.

View Block #1,348,649 on Chainz β†—
Circulating Supply:57,973,897 XPMΒ·at block #6,841,191 Β· updates every 60s
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AQZeJoQ81VgeHQBpEYTgvNqV1gnz3L5SvK

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