Block #431,827

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/6/2014, 11:29:37 AM · Difficulty 10.3433 · 6,374,250 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
54c6fca08873df97b0de42fe211087545593ae73a04361cfd042b7d73c52a5ea

Height

#431,827

Difficulty

10.343258

Transactions

2

Size

431 B

Version

2

Bits

0a57dfbf

Nonce

119,422

Timestamp

3/6/2014, 11:29:37 AM

Confirmations

6,374,250

Merkle Root

053c8562bfafe0f02b252c7e4c5d1ab3e802001aa0f0d19a57a15afe274dc4b9
Transactions (2)
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.

6.145 × 10⁹¹(92-digit number)
61455199243628054155…65298558548254328369
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
6.145 × 10⁹¹(92-digit number)
61455199243628054155…65298558548254328369
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.229 × 10⁹²(93-digit number)
12291039848725610831…30597117096508656739
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.458 × 10⁹²(93-digit number)
24582079697451221662…61194234193017313479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.916 × 10⁹²(93-digit number)
49164159394902443324…22388468386034626959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
9.832 × 10⁹²(93-digit number)
98328318789804886649…44776936772069253919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.966 × 10⁹³(94-digit number)
19665663757960977329…89553873544138507839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.933 × 10⁹³(94-digit number)
39331327515921954659…79107747088277015679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.866 × 10⁹³(94-digit number)
78662655031843909319…58215494176554031359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.573 × 10⁹⁴(95-digit number)
15732531006368781863…16430988353108062719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.146 × 10⁹⁴(95-digit number)
31465062012737563727…32861976706216125439
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:57,692,689 XPM·at block #6,806,076 · updates every 60s
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