Block #33,774

1CCLength 8★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 7/14/2013, 5:27:49 AM · Difficulty 7.9924 · 6,770,005 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d10303c5b273ef87c8608308fa463994da509fcc18b8a4300655573fe4871f20

Height

#33,774

Difficulty

7.992413

Transactions

1

Size

202 B

Version

2

Bits

07fe0eca

Nonce

1,378

Timestamp

7/14/2013, 5:27:49 AM

Confirmations

6,770,005

Merkle Root

f2cf218c46e80194b0d3cb32b4b096fe29382102196bb12f3df17da87ed225ad
Transactions (1)
1 in → 1 out15.6300 XPM109 B
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.

1.249 × 10¹⁰¹(102-digit number)
12497419222144501697…05075311085603202499
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
1.249 × 10¹⁰¹(102-digit number)
12497419222144501697…05075311085603202499
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.499 × 10¹⁰¹(102-digit number)
24994838444289003395…10150622171206404999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.998 × 10¹⁰¹(102-digit number)
49989676888578006790…20301244342412809999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
9.997 × 10¹⁰¹(102-digit number)
99979353777156013581…40602488684825619999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.999 × 10¹⁰²(103-digit number)
19995870755431202716…81204977369651239999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.999 × 10¹⁰²(103-digit number)
39991741510862405432…62409954739302479999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.998 × 10¹⁰²(103-digit number)
79983483021724810865…24819909478604959999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.599 × 10¹⁰³(104-digit number)
15996696604344962173…49639818957209919999
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 8 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 8

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:57,674,271 XPM·at block #6,803,778 · updates every 60s
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