Block #316,112

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 12/16/2013, 9:18:41 PM · Difficulty 10.1265 · 6,480,470 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
0efebf09f59ed05b3bde90c9bc8321e631796fc4138e6eac65df8fdba33a4a01

Height

#316,112

Difficulty

10.126482

Transactions

23

Size

7.80 KB

Version

2

Bits

0a206128

Nonce

50,855

Timestamp

12/16/2013, 9:18:41 PM

Confirmations

6,480,470

Merkle Root

7b8ed08172d93be5355915a78e9d323371d2dcd5990f26d5b592d745343e8803
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.

9.985 × 10⁹²(93-digit number)
99857702246403193059…66521505749060140799
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
9.985 × 10⁹²(93-digit number)
99857702246403193059…66521505749060140799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.997 × 10⁹³(94-digit number)
19971540449280638611…33043011498120281599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.994 × 10⁹³(94-digit number)
39943080898561277223…66086022996240563199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.988 × 10⁹³(94-digit number)
79886161797122554447…32172045992481126399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.597 × 10⁹⁴(95-digit number)
15977232359424510889…64344091984962252799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.195 × 10⁹⁴(95-digit number)
31954464718849021778…28688183969924505599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.390 × 10⁹⁴(95-digit number)
63908929437698043557…57376367939849011199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.278 × 10⁹⁵(96-digit number)
12781785887539608711…14752735879698022399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.556 × 10⁹⁵(96-digit number)
25563571775079217423…29505471759396044799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.112 × 10⁹⁵(96-digit number)
51127143550158434846…59010943518792089599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
1.022 × 10⁹⁶(97-digit number)
10225428710031686969…18021887037584179199
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:57,616,658 XPM·at block #6,796,581 · updates every 60s
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