Block #507,984

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/24/2014, 2:35:47 AM · Difficulty 10.8171 · 6,299,092 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
5787254993b0a28ec48cdc3b6695d60772c4e3cd7f7367bf043137c83748a0f8

Height

#507,984

Difficulty

10.817130

Transactions

2

Size

1.35 KB

Version

2

Bits

0ad12f68

Nonce

30,791,091

Timestamp

4/24/2014, 2:35:47 AM

Confirmations

6,299,092

Merkle Root

faead3feab1ecb4db1366fcc2936b98cd26322c80452146444de6b9105f4f662
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.

2.602 × 10⁹⁹(100-digit number)
26027384130027162814…84197482898684081601
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
2.602 × 10⁹⁹(100-digit number)
26027384130027162814…84197482898684081601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.205 × 10⁹⁹(100-digit number)
52054768260054325629…68394965797368163201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.041 × 10¹⁰⁰(101-digit number)
10410953652010865125…36789931594736326401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.082 × 10¹⁰⁰(101-digit number)
20821907304021730251…73579863189472652801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.164 × 10¹⁰⁰(101-digit number)
41643814608043460503…47159726378945305601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.328 × 10¹⁰⁰(101-digit number)
83287629216086921006…94319452757890611201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.665 × 10¹⁰¹(102-digit number)
16657525843217384201…88638905515781222401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.331 × 10¹⁰¹(102-digit number)
33315051686434768402…77277811031562444801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.663 × 10¹⁰¹(102-digit number)
66630103372869536805…54555622063124889601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.332 × 10¹⁰²(103-digit number)
13326020674573907361…09111244126249779201
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:57,700,704 XPM·at block #6,807,075 · updates every 60s
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