Block #337,081

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/31/2013, 10:15:14 AM · Difficulty 10.1396 · 6,457,321 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d38cc897f4a88181ba96969ff9cd3f22fb3e96ca52b8af945ae086eb195fe0da

Height

#337,081

Difficulty

10.139608

Transactions

6

Size

1.23 KB

Version

2

Bits

0a23bd5e

Nonce

102,198

Timestamp

12/31/2013, 10:15:14 AM

Confirmations

6,457,321

Merkle Root

b81a8ace7a58daf79c206dea3c87f9f662de672ae3aa0cd3749333d056273264
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.

5.322 × 10⁹⁶(97-digit number)
53226743845805406639…76885165909230151679
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
5.322 × 10⁹⁶(97-digit number)
53226743845805406639…76885165909230151679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.064 × 10⁹⁷(98-digit number)
10645348769161081327…53770331818460303359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.129 × 10⁹⁷(98-digit number)
21290697538322162655…07540663636920606719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.258 × 10⁹⁷(98-digit number)
42581395076644325311…15081327273841213439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.516 × 10⁹⁷(98-digit number)
85162790153288650623…30162654547682426879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.703 × 10⁹⁸(99-digit number)
17032558030657730124…60325309095364853759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.406 × 10⁹⁸(99-digit number)
34065116061315460249…20650618190729707519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.813 × 10⁹⁸(99-digit number)
68130232122630920498…41301236381459415039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.362 × 10⁹⁹(100-digit number)
13626046424526184099…82602472762918830079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.725 × 10⁹⁹(100-digit number)
27252092849052368199…65204945525837660159
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,599,247 XPM·at block #6,794,401 · updates every 60s
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