Block #134,911

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/26/2013, 7:54:06 AM · Difficulty 9.8073 · 6,668,545 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b8dd080d7bb1cc56a467a9a454cf7f4327c4ee70ac30d18483d09302e7553103

Height

#134,911

Difficulty

9.807263

Transactions

9

Size

2.39 KB

Version

2

Bits

09cea8c6

Nonce

125,851

Timestamp

8/26/2013, 7:54:06 AM

Confirmations

6,668,545

Merkle Root

560b90a796345c4944a691534ce7d5481cccfa901b9074fee67a9091e07190da
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.

2.211 × 10⁹³(94-digit number)
22116715680277915414…14110171246896986719
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
2.211 × 10⁹³(94-digit number)
22116715680277915414…14110171246896986719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.423 × 10⁹³(94-digit number)
44233431360555830828…28220342493793973439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.846 × 10⁹³(94-digit number)
88466862721111661656…56440684987587946879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.769 × 10⁹⁴(95-digit number)
17693372544222332331…12881369975175893759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.538 × 10⁹⁴(95-digit number)
35386745088444664662…25762739950351787519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.077 × 10⁹⁴(95-digit number)
70773490176889329325…51525479900703575039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.415 × 10⁹⁵(96-digit number)
14154698035377865865…03050959801407150079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.830 × 10⁹⁵(96-digit number)
28309396070755731730…06101919602814300159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.661 × 10⁹⁵(96-digit number)
56618792141511463460…12203839205628600319
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 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
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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,671,675 XPM·at block #6,803,455 · updates every 60s
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