Block #334,894

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/29/2013, 7:43:50 PM · Difficulty 10.1593 · 6,460,710 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
2064edcf963176f375cea44cbe1f7bc9931db1559101827febd7332eaf181d4f

Height

#334,894

Difficulty

10.159286

Transactions

27

Size

11.32 KB

Version

2

Bits

0a28c700

Nonce

242,617

Timestamp

12/29/2013, 7:43:50 PM

Confirmations

6,460,710

Merkle Root

0932ea404aba578ad9bb835688686af4dc0b3dfd1f000fd44f30fa51d4124905
Prime Chain Origin

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

7.686 × 10⁹⁷(98-digit number)
76860105427572012557…31555817975162646081
Discovered Prime Numbers
p_k = 2^k × 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
7.686 × 10⁹⁷(98-digit number)
76860105427572012557…31555817975162646081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.537 × 10⁹⁸(99-digit number)
15372021085514402511…63111635950325292161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.074 × 10⁹⁸(99-digit number)
30744042171028805023…26223271900650584321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.148 × 10⁹⁸(99-digit number)
61488084342057610046…52446543801301168641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.229 × 10⁹⁹(100-digit number)
12297616868411522009…04893087602602337281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.459 × 10⁹⁹(100-digit number)
24595233736823044018…09786175205204674561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.919 × 10⁹⁹(100-digit number)
49190467473646088036…19572350410409349121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
9.838 × 10⁹⁹(100-digit number)
98380934947292176073…39144700820818698241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.967 × 10¹⁰⁰(101-digit number)
19676186989458435214…78289401641637396481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.935 × 10¹⁰⁰(101-digit number)
39352373978916870429…56578803283274792961
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

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

★★☆☆☆
Rarity
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

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 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,608,895 XPM·at block #6,795,603 · updates every 60s
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