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Home/Chain Registry/Block #149,015

Block #149,015

2CCLength 9β˜…β˜†β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 9/4/2013, 2:22:40 AM Β· Difficulty 9.8567 Β· 6,675,788 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
249890a1ee3e8859bfb101056e9fe1a74231cb4e2538481c018c4bdba255becf
View on Chainz β†—

Height

#149,015

Difficulty

9.856716

Transactions

1

Size

198 B

Version

2

Bits

09db51c2

Nonce

82,937

Timestamp

9/4/2013, 2:22:40 AM

Confirmations

6,675,788

Merkle Root

e0a206e025ab6fa772d297d7cf016d350d68423835a0e94870548b1897190caa
Transactions (1)
Coinbasee0a206e025ab6f…548b1897190caa
1 in β†’ 1 out10.2800 XPM109 B
AVqdFe4j…cahQY1EY
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.

2.423 Γ— 10⁹³(94-digit number)
24237849119870525561…27282343119683460800
Discovered Prime Numbers
p_k = 2^k Γ— origin + 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 + 1
2.423 Γ— 10⁹³(94-digit number)
24237849119870525561…27282343119683460801
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
4.847 Γ— 10⁹³(94-digit number)
48475698239741051123…54564686239366921601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
9.695 Γ— 10⁹³(94-digit number)
96951396479482102246…09129372478733843201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
1.939 Γ— 10⁹⁴(95-digit number)
19390279295896420449…18258744957467686401
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
3.878 Γ— 10⁹⁴(95-digit number)
38780558591792840898…36517489914935372801
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
7.756 Γ— 10⁹⁴(95-digit number)
77561117183585681796…73034979829870745601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
1.551 Γ— 10⁹⁡(96-digit number)
15512223436717136359…46069959659741491201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
3.102 Γ— 10⁹⁡(96-digit number)
31024446873434272718…92139919319482982401
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
6.204 Γ— 10⁹⁡(96-digit number)
62048893746868545437…84279838638965964801
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 Second 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 2CC formula:

2CC: p₁ (first prime), pβ‚‚ = 2p₁ βˆ’ 1, p₃ = 2pβ‚‚ βˆ’ 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 149015

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 249890a1ee3e8859bfb101056e9fe1a74231cb4e2538481c018c4bdba255becf

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 #149,015 on Chainz β†—
Circulating Supply:57,842,500 XPMΒ·at block #6,824,802 Β· updates every 60s
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