Block #904,832

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/22/2015, 5:20:11 AM · Difficulty 10.9366 · 5,891,305 confirmations

1CC

Cunningham Chain of the First Kind

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

Block Header

Block Hash

292622d98010f45f53035e87e407f5c73a04283494027913125d946dc42b0b1e

View on Chainz ↗

Height

#904,832

Difficulty

10.936612

Transactions

Size

580 B

Version

Bits

0aefc5cc

Nonce

539,521,057

Timestamp

1/22/2015, 5:20:11 AM

Confirmations

5,891,305

Mined by

⛏️ P2SHANSXnLY2HX2a5e6fdcDUZDtfwTSd25TjkD

Merkle Root

ab0a71aa5c08c7bfcf8a329dd5bd3c69ceeed35c92062849ad11ddb5d5275e98

Transactions (2)

Coinbase61a02f0200193d…09304770b523ce

1 in → 1 out8.3600 XPM116 B

ANSXnLY2…Sd25TjkD

81472c80a022bb…aa5ee7b5d3219d

2 in → 2 out211.0129 XPM374 B

ATV9554f…cvQffAQx ARMdYjzi…yaTZG7Sj

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.

7.490 × 10⁹³(94-digit number)

74907922094636023096…72707809073520372199

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.

origin − 1

7.490 × 10⁹³(94-digit number)

74907922094636023096…72707809073520372199

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^1 × origin − 1

1.498 × 10⁹⁴(95-digit number)

14981584418927204619…45415618147040744399

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^2 × origin − 1

2.996 × 10⁹⁴(95-digit number)

29963168837854409238…90831236294081488799

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^3 × origin − 1

5.992 × 10⁹⁴(95-digit number)

59926337675708818477…81662472588162977599

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^4 × origin − 1

1.198 × 10⁹⁵(96-digit number)

11985267535141763695…63324945176325955199

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^5 × origin − 1

2.397 × 10⁹⁵(96-digit number)

23970535070283527390…26649890352651910399

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^6 × origin − 1

4.794 × 10⁹⁵(96-digit number)

47941070140567054781…53299780705303820799

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^7 × origin − 1

9.588 × 10⁹⁵(96-digit number)

95882140281134109563…06599561410607641599

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^8 × origin − 1

1.917 × 10⁹⁶(97-digit number)

19176428056226821912…13199122821215283199

Verify on FactorDB ↗Wolfram Alpha ↗

×2+1 →

2^9 × origin − 1

3.835 × 10⁹⁶(97-digit number)

38352856112453643825…26398245642430566399

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, …

Cross-reference on Chainz Explorer