Block #146,035

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 9/2/2013, 6:21:36 AM · Difficulty 9.8466 · 6,659,138 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
14e59fc2806951f2d0cd71b0c1527447d9aabe49be25a40e548d57d3dede7a7b

Height

#146,035

Difficulty

9.846551

Transactions

3

Size

1.68 KB

Version

2

Bits

09d8b799

Nonce

81,538

Timestamp

9/2/2013, 6:21:36 AM

Confirmations

6,659,138

Merkle Root

0ab81d9d6e1bd89faebbaa01dd00a74dec0172cc40209d55c4a4e5b90f578552
Transactions (3)
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.

4.274 × 10⁹⁴(95-digit number)
42743086851016749166…45388322553669034381
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
4.274 × 10⁹⁴(95-digit number)
42743086851016749166…45388322553669034381
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.548 × 10⁹⁴(95-digit number)
85486173702033498333…90776645107338068761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.709 × 10⁹⁵(96-digit number)
17097234740406699666…81553290214676137521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.419 × 10⁹⁵(96-digit number)
34194469480813399333…63106580429352275041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.838 × 10⁹⁵(96-digit number)
68388938961626798666…26213160858704550081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.367 × 10⁹⁶(97-digit number)
13677787792325359733…52426321717409100161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.735 × 10⁹⁶(97-digit number)
27355575584650719466…04852643434818200321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.471 × 10⁹⁶(97-digit number)
54711151169301438933…09705286869636400641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.094 × 10⁹⁷(98-digit number)
10942230233860287786…19410573739272801281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.188 × 10⁹⁷(98-digit number)
21884460467720575573…38821147478545602561
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:57,685,452 XPM·at block #6,805,172 · updates every 60s
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