Block #1,060,272

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/15/2015, 9:59:11 AM · Difficulty 10.7275 · 5,745,702 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
aee74598b2ba65632c9287a4a0e66c262d4cd8782f1e5fdd14ca8b5740213c83

Height

#1,060,272

Difficulty

10.727490

Transactions

12

Size

4.08 KB

Version

2

Bits

0aba3cc7

Nonce

249,865,950

Timestamp

5/15/2015, 9:59:11 AM

Confirmations

5,745,702

Merkle Root

cb4247cbe172d0eed075636d666ca62ba07cd77a2be6c34b1cf4c269e391d3fc
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.

8.967 × 10⁹⁴(95-digit number)
89673466303269541766…66472232670518985201
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
8.967 × 10⁹⁴(95-digit number)
89673466303269541766…66472232670518985201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.793 × 10⁹⁵(96-digit number)
17934693260653908353…32944465341037970401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.586 × 10⁹⁵(96-digit number)
35869386521307816706…65888930682075940801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.173 × 10⁹⁵(96-digit number)
71738773042615633413…31777861364151881601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.434 × 10⁹⁶(97-digit number)
14347754608523126682…63555722728303763201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.869 × 10⁹⁶(97-digit number)
28695509217046253365…27111445456607526401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.739 × 10⁹⁶(97-digit number)
57391018434092506730…54222890913215052801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.147 × 10⁹⁷(98-digit number)
11478203686818501346…08445781826430105601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.295 × 10⁹⁷(98-digit number)
22956407373637002692…16891563652860211201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.591 × 10⁹⁷(98-digit number)
45912814747274005384…33783127305720422401
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,691,867 XPM·at block #6,805,973 · updates every 60s
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