Block #922,258

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 2/4/2015, 8:04:18 AM · Difficulty 10.9160 · 5,871,986 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
190b6797041b8b4209c004d69056aa19833be34f8d4256da8bbcc95e372d3f68

Height

#922,258

Difficulty

10.916003

Transactions

6

Size

116.34 KB

Version

2

Bits

0aea7f2f

Nonce

100,695,901

Timestamp

2/4/2015, 8:04:18 AM

Confirmations

5,871,986

Merkle Root

1ea8ca864fe1f90e9845179cdebf2ab84980dcc2967c57a5f3d7e12443f9471f
Transactions (6)
1 in → 1 out9.5900 XPM116 B
200 in → 1 out1057.4263 XPM28.94 KB
200 in → 1 out975.5917 XPM28.93 KB
200 in → 1 out1032.9464 XPM28.93 KB
200 in → 1 out1033.7498 XPM28.94 KB
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.

5.348 × 10⁹⁶(97-digit number)
53489242198277698328…41216589258528516159
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
5.348 × 10⁹⁶(97-digit number)
53489242198277698328…41216589258528516159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.069 × 10⁹⁷(98-digit number)
10697848439655539665…82433178517057032319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.139 × 10⁹⁷(98-digit number)
21395696879311079331…64866357034114064639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.279 × 10⁹⁷(98-digit number)
42791393758622158662…29732714068228129279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.558 × 10⁹⁷(98-digit number)
85582787517244317325…59465428136456258559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.711 × 10⁹⁸(99-digit number)
17116557503448863465…18930856272912517119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.423 × 10⁹⁸(99-digit number)
34233115006897726930…37861712545825034239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.846 × 10⁹⁸(99-digit number)
68466230013795453860…75723425091650068479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.369 × 10⁹⁹(100-digit number)
13693246002759090772…51446850183300136959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.738 × 10⁹⁹(100-digit number)
27386492005518181544…02893700366600273919
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:57,597,984 XPM·at block #6,794,243 · updates every 60s
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