Block #711,243

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 9/7/2014, 6:12:54 PM · Difficulty 10.9560 · 6,094,767 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
f4eed3c4bf4cb285ab97812a4f7d731d9e1c76768d3eb6e134c81ea785b83e89

Height

#711,243

Difficulty

10.956050

Transactions

3

Size

624 B

Version

2

Bits

0af4bfae

Nonce

87,480,333

Timestamp

9/7/2014, 6:12:54 PM

Confirmations

6,094,767

Merkle Root

e96de87c130b865926110c0eb5c2006653307c45b51c5185bf35ca3a02b7a282
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.

1.331 × 10⁹⁵(96-digit number)
13314512508052509858…68971467492567514039
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
1.331 × 10⁹⁵(96-digit number)
13314512508052509858…68971467492567514039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.662 × 10⁹⁵(96-digit number)
26629025016105019717…37942934985135028079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.325 × 10⁹⁵(96-digit number)
53258050032210039434…75885869970270056159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.065 × 10⁹⁶(97-digit number)
10651610006442007886…51771739940540112319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.130 × 10⁹⁶(97-digit number)
21303220012884015773…03543479881080224639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.260 × 10⁹⁶(97-digit number)
42606440025768031547…07086959762160449279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
8.521 × 10⁹⁶(97-digit number)
85212880051536063095…14173919524320898559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.704 × 10⁹⁷(98-digit number)
17042576010307212619…28347839048641797119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.408 × 10⁹⁷(98-digit number)
34085152020614425238…56695678097283594239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.817 × 10⁹⁷(98-digit number)
68170304041228850476…13391356194567188479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
1.363 × 10⁹⁸(99-digit number)
13634060808245770095…26782712389134376959
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,692,158 XPM·at block #6,806,009 · updates every 60s
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