Block #82,127

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 7/25/2013, 5:14:27 AM · Difficulty 9.2749 · 6,723,923 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
5eab512ad9c8746661cf95d2d7ff9d7eeddd1eb7c46eccf1f7b19e1d7940001f

Height

#82,127

Difficulty

9.274910

Transactions

2

Size

3.02 KB

Version

2

Bits

09466087

Nonce

341

Timestamp

7/25/2013, 5:14:27 AM

Confirmations

6,723,923

Merkle Root

c2c799429e263176d602392259e5e1337236da0d7b35d203cf7e7c486a804ee9
Transactions (2)
1 in → 1 out11.6400 XPM110 B
25 in → 1 out293.3000 XPM2.82 KB
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.

8.033 × 10⁹¹(92-digit number)
80332812112842182409…65416496670887066599
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
8.033 × 10⁹¹(92-digit number)
80332812112842182409…65416496670887066599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.606 × 10⁹²(93-digit number)
16066562422568436481…30832993341774133199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.213 × 10⁹²(93-digit number)
32133124845136872963…61665986683548266399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.426 × 10⁹²(93-digit number)
64266249690273745927…23331973367096532799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.285 × 10⁹³(94-digit number)
12853249938054749185…46663946734193065599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.570 × 10⁹³(94-digit number)
25706499876109498370…93327893468386131199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.141 × 10⁹³(94-digit number)
51412999752218996741…86655786936772262399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.028 × 10⁹⁴(95-digit number)
10282599950443799348…73311573873544524799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.056 × 10⁹⁴(95-digit number)
20565199900887598696…46623147747089049599
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:57,692,482 XPM·at block #6,806,049 · updates every 60s
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