Block #413,014

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 2/20/2014, 10:32:56 PM · Difficulty 10.4174 · 6,397,716 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
af2033d70c251051039789ea24fcfbefd253fb54f01a09fb851cdd1f2e35fd64

Height

#413,014

Difficulty

10.417375

Transactions

10

Size

2.33 KB

Version

2

Bits

0a6ad91d

Nonce

130,527

Timestamp

2/20/2014, 10:32:56 PM

Confirmations

6,397,716

Merkle Root

1f6882320c7bce9dc923bc7005a11d06339a1e1d424d4d9ce1da04bc9046984b
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.

4.009 × 10¹⁰¹(102-digit number)
40098325482360718029…68998714278578717441
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
4.009 × 10¹⁰¹(102-digit number)
40098325482360718029…68998714278578717441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.019 × 10¹⁰¹(102-digit number)
80196650964721436059…37997428557157434881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.603 × 10¹⁰²(103-digit number)
16039330192944287211…75994857114314869761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.207 × 10¹⁰²(103-digit number)
32078660385888574423…51989714228629739521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.415 × 10¹⁰²(103-digit number)
64157320771777148847…03979428457259479041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.283 × 10¹⁰³(104-digit number)
12831464154355429769…07958856914518958081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.566 × 10¹⁰³(104-digit number)
25662928308710859539…15917713829037916161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.132 × 10¹⁰³(104-digit number)
51325856617421719078…31835427658075832321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.026 × 10¹⁰⁴(105-digit number)
10265171323484343815…63670855316151664641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.053 × 10¹⁰⁴(105-digit number)
20530342646968687631…27341710632303329281
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:57,729,930 XPM·at block #6,810,729 · updates every 60s
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