Block #461,046

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/26/2014, 11:05:22 AM · Difficulty 10.4154 · 6,337,336 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
571cd50c41a343cc3f0b77c12eb8d5da250cd56e736a0712debdf7dd757be0f7

Height

#461,046

Difficulty

10.415364

Transactions

8

Size

2.55 KB

Version

2

Bits

0a6a5546

Nonce

203,505

Timestamp

3/26/2014, 11:05:22 AM

Confirmations

6,337,336

Merkle Root

ba7bbafaeafa2a8e76ee65341a4e8d79212b782623f0b60ac5d4601569c13028
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.

4.109 × 10¹⁰¹(102-digit number)
41092118097174092829…14775021692648351361
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
4.109 × 10¹⁰¹(102-digit number)
41092118097174092829…14775021692648351361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.218 × 10¹⁰¹(102-digit number)
82184236194348185658…29550043385296702721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.643 × 10¹⁰²(103-digit number)
16436847238869637131…59100086770593405441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.287 × 10¹⁰²(103-digit number)
32873694477739274263…18200173541186810881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.574 × 10¹⁰²(103-digit number)
65747388955478548526…36400347082373621761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.314 × 10¹⁰³(104-digit number)
13149477791095709705…72800694164747243521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.629 × 10¹⁰³(104-digit number)
26298955582191419410…45601388329494487041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.259 × 10¹⁰³(104-digit number)
52597911164382838821…91202776658988974081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.051 × 10¹⁰⁴(105-digit number)
10519582232876567764…82405553317977948161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.103 × 10¹⁰⁴(105-digit number)
21039164465753135528…64811106635955896321
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:57,631,062 XPM·at block #6,798,381 · updates every 60s
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