Block #2,245,037

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 8/10/2017, 7:47:21 AM · Difficulty 10.9472 · 4,558,723 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
2c2351274bca23c53b63304d5a0d466a0da4d26b293b809bef94412b445caed3

Height

#2,245,037

Difficulty

10.947186

Transactions

5

Size

1.08 KB

Version

2

Bits

0af27acb

Nonce

322,379,077

Timestamp

8/10/2017, 7:47:21 AM

Confirmations

4,558,723

Merkle Root

4c73bae6c46db52b675808733ce1e2cbffdf6c3539343275100d0e12e6b022e8
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.

1.623 × 10⁹⁴(95-digit number)
16236787510000783994…48213924114388818879
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
1.623 × 10⁹⁴(95-digit number)
16236787510000783994…48213924114388818879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.247 × 10⁹⁴(95-digit number)
32473575020001567989…96427848228777637759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
6.494 × 10⁹⁴(95-digit number)
64947150040003135979…92855696457555275519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.298 × 10⁹⁵(96-digit number)
12989430008000627195…85711392915110551039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.597 × 10⁹⁵(96-digit number)
25978860016001254391…71422785830221102079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
5.195 × 10⁹⁵(96-digit number)
51957720032002508783…42845571660442204159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.039 × 10⁹⁶(97-digit number)
10391544006400501756…85691143320884408319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.078 × 10⁹⁶(97-digit number)
20783088012801003513…71382286641768816639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.156 × 10⁹⁶(97-digit number)
41566176025602007026…42764573283537633279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
8.313 × 10⁹⁶(97-digit number)
83132352051204014053…85529146567075266559
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:57,674,120 XPM·at block #6,803,759 · updates every 60s
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