Block #316,596

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/17/2013, 4:21:31 AM · Difficulty 10.1374 · 6,490,746 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
516522d374e7ad6356fe3daa3445b6e420a98bda13928eca3aa0a746514286cc

Height

#316,596

Difficulty

10.137390

Transactions

37

Size

12.18 KB

Version

2

Bits

0a232bf9

Nonce

620,285

Timestamp

12/17/2013, 4:21:31 AM

Confirmations

6,490,746

Merkle Root

d6a403d2e5bc7772078952bac317dd96d4aa5efbcf8af844ff91a15c559e0fe8
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.

1.942 × 10¹⁰¹(102-digit number)
19426492497676511238…59783379314519234559
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
1.942 × 10¹⁰¹(102-digit number)
19426492497676511238…59783379314519234559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.885 × 10¹⁰¹(102-digit number)
38852984995353022477…19566758629038469119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.770 × 10¹⁰¹(102-digit number)
77705969990706044954…39133517258076938239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.554 × 10¹⁰²(103-digit number)
15541193998141208990…78267034516153876479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.108 × 10¹⁰²(103-digit number)
31082387996282417981…56534069032307752959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.216 × 10¹⁰²(103-digit number)
62164775992564835963…13068138064615505919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.243 × 10¹⁰³(104-digit number)
12432955198512967192…26136276129231011839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.486 × 10¹⁰³(104-digit number)
24865910397025934385…52272552258462023679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.973 × 10¹⁰³(104-digit number)
49731820794051868770…04545104516924047359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
9.946 × 10¹⁰³(104-digit number)
99463641588103737541…09090209033848094719
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:57,702,755 XPM·at block #6,807,341 · updates every 60s
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