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Block #63,270

1CCLength 9β˜…β˜†β˜†β˜†β˜†

Cunningham Chain of the First Kind Β· Discovered 7/19/2013, 12:23:04 AM Β· Difficulty 8.9787 Β· 6,763,333 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
618a0bf1e107390ab82e8ef522a16f622f587f3680e0646452ffd083ee94b409
View on Chainz β†—

Height

#63,270

Difficulty

8.978736

Transactions

2

Size

689 B

Version

2

Bits

08fa8e75

Nonce

1,060

Timestamp

7/19/2013, 12:23:04 AM

Confirmations

6,763,333

Merkle Root

b4d9c26b85097293ec1cc5ede64c8920fe031282eed923364066506905bba60d
Transactions (2)
Coinbaseec5994b7a7f90e…a122803d4efc11
1 in β†’ 1 out12.4000 XPM110 B
ASDj1wuQ…J77yXWvJ
1426825dcbcf70…d22f8836665b7e
3 in β†’ 2 out100.0200 XPM489 B
Aeuippbq…5LWvrrYLAHmCF2NT…PH86aghT
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.

1.549 Γ— 10⁹⁴(95-digit number)
15494635173598583175…70922720609041330180
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
1.549 Γ— 10⁹⁴(95-digit number)
15494635173598583175…70922720609041330179
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
2
2^1 Γ— origin βˆ’ 1
3.098 Γ— 10⁹⁴(95-digit number)
30989270347197166350…41845441218082660359
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
3
2^2 Γ— origin βˆ’ 1
6.197 Γ— 10⁹⁴(95-digit number)
61978540694394332701…83690882436165320719
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
4
2^3 Γ— origin βˆ’ 1
1.239 Γ— 10⁹⁡(96-digit number)
12395708138878866540…67381764872330641439
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
5
2^4 Γ— origin βˆ’ 1
2.479 Γ— 10⁹⁡(96-digit number)
24791416277757733080…34763529744661282879
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
6
2^5 Γ— origin βˆ’ 1
4.958 Γ— 10⁹⁡(96-digit number)
49582832555515466161…69527059489322565759
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
7
2^6 Γ— origin βˆ’ 1
9.916 Γ— 10⁹⁡(96-digit number)
99165665111030932322…39054118978645131519
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
8
2^7 Γ— origin βˆ’ 1
1.983 Γ— 10⁹⁢(97-digit number)
19833133022206186464…78108237957290263039
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2+1 β†’
9
2^8 Γ— origin βˆ’ 1
3.966 Γ— 10⁹⁢(97-digit number)
39666266044412372929…56216475914580526079
Verify on FactorDB β†—Wolfram Alpha β†—

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9
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 63270

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 618a0bf1e107390ab82e8ef522a16f622f587f3680e0646452ffd083ee94b409

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 #63,270 on Chainz β†—
Circulating Supply:57,856,976 XPMΒ·at block #6,826,602 Β· updates every 60s
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