Block #325,876

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/23/2013, 9:28:14 AM · Difficulty 10.1953 · 6,477,447 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
c003a5eacdf4f5d536a64738ba4d08dcf707362e358ab299610872d92d7fa7c6

Height

#325,876

Difficulty

10.195315

Transactions

7

Size

2.62 KB

Version

2

Bits

0a32002a

Nonce

39,711

Timestamp

12/23/2013, 9:28:14 AM

Confirmations

6,477,447

Merkle Root

c5aad19a64dc36077e350962bd62edc06bede04a1946b9c8c4d2b8b4cf3021ca
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.

1.039 × 10¹⁰¹(102-digit number)
10392825802756326087…58576049583491106159
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
1.039 × 10¹⁰¹(102-digit number)
10392825802756326087…58576049583491106159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.078 × 10¹⁰¹(102-digit number)
20785651605512652174…17152099166982212319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.157 × 10¹⁰¹(102-digit number)
41571303211025304349…34304198333964424639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.314 × 10¹⁰¹(102-digit number)
83142606422050608699…68608396667928849279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.662 × 10¹⁰²(103-digit number)
16628521284410121739…37216793335857698559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.325 × 10¹⁰²(103-digit number)
33257042568820243479…74433586671715397119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.651 × 10¹⁰²(103-digit number)
66514085137640486959…48867173343430794239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.330 × 10¹⁰³(104-digit number)
13302817027528097391…97734346686861588479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.660 × 10¹⁰³(104-digit number)
26605634055056194783…95468693373723176959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.321 × 10¹⁰³(104-digit number)
53211268110112389567…90937386747446353919
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:57,670,614 XPM·at block #6,803,322 · updates every 60s
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