Block #376,797

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/26/2014, 3:51:22 PM · Difficulty 10.4266 · 6,422,558 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
c70bf2f7e5a729e98a8a2dd6cec7651aa872a21020646721bea49ab2f53e0f65

Height

#376,797

Difficulty

10.426611

Transactions

10

Size

8.95 KB

Version

2

Bits

0a6d3668

Nonce

797,903

Timestamp

1/26/2014, 3:51:22 PM

Confirmations

6,422,558

Merkle Root

815af0bc5189494bbfd8f8d1e0a5ba83b9d019d7c2a3ea42332d469ca30df773
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.

1.154 × 10¹⁰³(104-digit number)
11546457990904716423…30845988985555472639
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
1.154 × 10¹⁰³(104-digit number)
11546457990904716423…30845988985555472639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.309 × 10¹⁰³(104-digit number)
23092915981809432847…61691977971110945279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.618 × 10¹⁰³(104-digit number)
46185831963618865695…23383955942221890559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
9.237 × 10¹⁰³(104-digit number)
92371663927237731391…46767911884443781119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.847 × 10¹⁰⁴(105-digit number)
18474332785447546278…93535823768887562239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.694 × 10¹⁰⁴(105-digit number)
36948665570895092556…87071647537775124479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.389 × 10¹⁰⁴(105-digit number)
73897331141790185112…74143295075550248959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.477 × 10¹⁰⁵(106-digit number)
14779466228358037022…48286590151100497919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.955 × 10¹⁰⁵(106-digit number)
29558932456716074045…96573180302200995839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.911 × 10¹⁰⁵(106-digit number)
59117864913432148090…93146360604401991679
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:57,638,885 XPM·at block #6,799,354 · updates every 60s
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