Block #957,811

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/2/2015, 12:52:18 AM · Difficulty 10.8897 · 5,836,796 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
1c0fed62dac66ffb2d6e192c1e361cc0feef3e98006d3148b099910d1a365b03

Height

#957,811

Difficulty

10.889668

Transactions

12

Size

2.56 KB

Version

2

Bits

0ae3c14c

Nonce

581,425,620

Timestamp

3/2/2015, 12:52:18 AM

Confirmations

5,836,796

Merkle Root

703081f6b33a046529eb9a391a0629e1ddc501a677fea24a72d7f0df46c1bcd1
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.

4.761 × 10⁹⁵(96-digit number)
47612462896815596890…70105243904589426439
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
4.761 × 10⁹⁵(96-digit number)
47612462896815596890…70105243904589426439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
9.522 × 10⁹⁵(96-digit number)
95224925793631193780…40210487809178852879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.904 × 10⁹⁶(97-digit number)
19044985158726238756…80420975618357705759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.808 × 10⁹⁶(97-digit number)
38089970317452477512…60841951236715411519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.617 × 10⁹⁶(97-digit number)
76179940634904955024…21683902473430823039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.523 × 10⁹⁷(98-digit number)
15235988126980991004…43367804946861646079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.047 × 10⁹⁷(98-digit number)
30471976253961982009…86735609893723292159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.094 × 10⁹⁷(98-digit number)
60943952507923964019…73471219787446584319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.218 × 10⁹⁸(99-digit number)
12188790501584792803…46942439574893168639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.437 × 10⁹⁸(99-digit number)
24377581003169585607…93884879149786337279
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,600,899 XPM·at block #6,794,606 · updates every 60s
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