Block #922,377

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 2/4/2015, 10:32:04 AM · Difficulty 10.9155 · 5,868,627 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
37b9703b829045283b96adcd1c9d0ec361719e2546c97a1d6244fe37556cc40c

Height

#922,377

Difficulty

10.915538

Transactions

12

Size

318.62 KB

Version

2

Bits

0aea60b0

Nonce

359,320,463

Timestamp

2/4/2015, 10:32:04 AM

Confirmations

5,868,627

Merkle Root

05d7e0f7311e10d8fa403274d114135e6997722e118ea62b4d5ed65c0f7d1f14
Transactions (12)
1 in → 1 out11.6800 XPM109 B
200 in → 1 out1078.2436 XPM28.95 KB
200 in → 1 out1043.1108 XPM28.94 KB
200 in → 1 out1083.2058 XPM28.94 KB
200 in → 1 out829.2612 XPM28.94 KB
200 in → 1 out1161.1565 XPM28.94 KB
200 in → 1 out1041.2003 XPM28.94 KB
200 in → 1 out1038.4710 XPM28.95 KB
200 in → 1 out911.1816 XPM28.95 KB
200 in → 1 out950.7916 XPM28.95 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.

5.397 × 10⁹⁶(97-digit number)
53976542700391460390…57090700317148840959
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
5.397 × 10⁹⁶(97-digit number)
53976542700391460390…57090700317148840959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.079 × 10⁹⁷(98-digit number)
10795308540078292078…14181400634297681919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.159 × 10⁹⁷(98-digit number)
21590617080156584156…28362801268595363839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.318 × 10⁹⁷(98-digit number)
43181234160313168312…56725602537190727679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.636 × 10⁹⁷(98-digit number)
86362468320626336624…13451205074381455359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.727 × 10⁹⁸(99-digit number)
17272493664125267324…26902410148762910719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.454 × 10⁹⁸(99-digit number)
34544987328250534649…53804820297525821439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.908 × 10⁹⁸(99-digit number)
69089974656501069299…07609640595051642879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.381 × 10⁹⁹(100-digit number)
13817994931300213859…15219281190103285759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.763 × 10⁹⁹(100-digit number)
27635989862600427719…30438562380206571519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
5.527 × 10⁹⁹(100-digit number)
55271979725200855439…60877124760413143039
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,572,047 XPM·at block #6,791,003 · updates every 60s