Block #101,845

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/6/2013, 8:27:30 PM · Difficulty 9.4745 · 6,700,844 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
12ea285807bee4f71bcae742b3dcfff8cea86fcc36cf52eee668c7a2960e8d35

Height

#101,845

Difficulty

9.474473

Transactions

4

Size

2.56 KB

Version

2

Bits

09797716

Nonce

200,809

Timestamp

8/6/2013, 8:27:30 PM

Confirmations

6,700,844

Merkle Root

cca764a3b694b96949a9b9fae5081a2df9ad21cf8d3db473b0f4d536e556d401
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.

1.481 × 10⁹⁸(99-digit number)
14813760328575888573…48941178795546385399
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
1.481 × 10⁹⁸(99-digit number)
14813760328575888573…48941178795546385399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.962 × 10⁹⁸(99-digit number)
29627520657151777146…97882357591092770799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.925 × 10⁹⁸(99-digit number)
59255041314303554293…95764715182185541599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.185 × 10⁹⁹(100-digit number)
11851008262860710858…91529430364371083199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.370 × 10⁹⁹(100-digit number)
23702016525721421717…83058860728742166399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.740 × 10⁹⁹(100-digit number)
47404033051442843434…66117721457484332799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.480 × 10⁹⁹(100-digit number)
94808066102885686869…32235442914968665599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.896 × 10¹⁰⁰(101-digit number)
18961613220577137373…64470885829937331199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.792 × 10¹⁰⁰(101-digit number)
37923226441154274747…28941771659874662399
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:57,665,534 XPM·at block #6,802,688 · updates every 60s
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