Block #92,259

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/1/2013, 2:07:43 PM · Difficulty 9.2032 · 6,699,198 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
a74db3b12eea3e88dbef0c3dcd2b18cfbeabcb01f12a54e4b13187e6d562090d

Height

#92,259

Difficulty

9.203162

Transactions

6

Size

3.51 KB

Version

2

Bits

09340268

Nonce

241,254

Timestamp

8/1/2013, 2:07:43 PM

Confirmations

6,699,198

Merkle Root

0193c0befdaf6a7cce4384445289da1329562f9619ae2e758462b8194b220164
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.

2.113 × 10¹⁰⁴(105-digit number)
21131849816356297701…55514347197174900179
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
2.113 × 10¹⁰⁴(105-digit number)
21131849816356297701…55514347197174900179
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.226 × 10¹⁰⁴(105-digit number)
42263699632712595402…11028694394349800359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.452 × 10¹⁰⁴(105-digit number)
84527399265425190804…22057388788699600719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.690 × 10¹⁰⁵(106-digit number)
16905479853085038160…44114777577399201439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.381 × 10¹⁰⁵(106-digit number)
33810959706170076321…88229555154798402879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.762 × 10¹⁰⁵(106-digit number)
67621919412340152643…76459110309596805759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.352 × 10¹⁰⁶(107-digit number)
13524383882468030528…52918220619193611519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.704 × 10¹⁰⁶(107-digit number)
27048767764936061057…05836441238387223039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.409 × 10¹⁰⁶(107-digit number)
54097535529872122114…11672882476774446079
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:57,575,599 XPM·at block #6,791,456 · updates every 60s
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