Block #88,119

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 7/29/2013, 9:21:40 AM · Difficulty 9.2730 · 6,701,851 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
a1308c2e65ede646548a732a079db90eb12e0520afbe27dd725f55572e13838d

Height

#88,119

Difficulty

9.272978

Transactions

3

Size

17.13 KB

Version

2

Bits

0945e1e3

Nonce

182,588

Timestamp

7/29/2013, 9:21:40 AM

Confirmations

6,701,851

Merkle Root

14cc929f0f1bf0636e9348489afc8082a3e82d87ff92fda6e04b7cb3e3c494b4
Transactions (3)
1 in → 1 out11.8000 XPM109 B
149 in → 1 out4218.9610 XPM16.79 KB
1 in → 1 out11.6300 XPM157 B
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.

4.183 × 10⁹⁵(96-digit number)
41836410609069888745…31338856817932042851
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
4.183 × 10⁹⁵(96-digit number)
41836410609069888745…31338856817932042851
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.367 × 10⁹⁵(96-digit number)
83672821218139777490…62677713635864085701
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.673 × 10⁹⁶(97-digit number)
16734564243627955498…25355427271728171401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.346 × 10⁹⁶(97-digit number)
33469128487255910996…50710854543456342801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.693 × 10⁹⁶(97-digit number)
66938256974511821992…01421709086912685601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.338 × 10⁹⁷(98-digit number)
13387651394902364398…02843418173825371201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.677 × 10⁹⁷(98-digit number)
26775302789804728796…05686836347650742401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.355 × 10⁹⁷(98-digit number)
53550605579609457593…11373672695301484801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.071 × 10⁹⁸(99-digit number)
10710121115921891518…22747345390602969601
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,563,737 XPM·at block #6,789,969 · updates every 60s