Block #479,157

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/7/2014, 12:55:19 PM · Difficulty 10.5010 · 6,319,852 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
5fc6e798e25ef85390dfa57abf3b32627900b6a3f5e5ca73ca8fb6879f2503f5

Height

#479,157

Difficulty

10.501043

Transactions

3

Size

1.81 KB

Version

2

Bits

0a804453

Nonce

4,272,115

Timestamp

4/7/2014, 12:55:19 PM

Confirmations

6,319,852

Merkle Root

6ecb9d42eca9839a8bbb0ddf305f8f95d3502fc2842dc492fda27ba4ff78e995
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.

2.000 × 10⁹⁸(99-digit number)
20001587607760000031…95947529585290111361
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
2.000 × 10⁹⁸(99-digit number)
20001587607760000031…95947529585290111361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.000 × 10⁹⁸(99-digit number)
40003175215520000063…91895059170580222721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
8.000 × 10⁹⁸(99-digit number)
80006350431040000126…83790118341160445441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.600 × 10⁹⁹(100-digit number)
16001270086208000025…67580236682320890881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.200 × 10⁹⁹(100-digit number)
32002540172416000050…35160473364641781761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
6.400 × 10⁹⁹(100-digit number)
64005080344832000100…70320946729283563521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.280 × 10¹⁰⁰(101-digit number)
12801016068966400020…40641893458567127041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.560 × 10¹⁰⁰(101-digit number)
25602032137932800040…81283786917134254081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
5.120 × 10¹⁰⁰(101-digit number)
51204064275865600080…62567573834268508161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.024 × 10¹⁰¹(102-digit number)
10240812855173120016…25135147668537016321
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:57,636,114 XPM·at block #6,799,008 · updates every 60s
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