Block #337,963

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/1/2014, 2:19:11 AM · Difficulty 10.1254 · 6,456,914 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
2474ff50d8d5c82bced8a7303886847d209684b02e03e8e6c6eecee0f933149a

Height

#337,963

Difficulty

10.125424

Transactions

5

Size

1.08 KB

Version

2

Bits

0a201bc7

Nonce

132,092

Timestamp

1/1/2014, 2:19:11 AM

Confirmations

6,456,914

Merkle Root

76ae55694206376aa206aabe5be711cab93d34de03ccfd6b4bcfcd787c2b5d88
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.

4.851 × 10¹⁰¹(102-digit number)
48512174956750673171…14670821292992885441
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
4.851 × 10¹⁰¹(102-digit number)
48512174956750673171…14670821292992885441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.702 × 10¹⁰¹(102-digit number)
97024349913501346342…29341642585985770881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.940 × 10¹⁰²(103-digit number)
19404869982700269268…58683285171971541761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.880 × 10¹⁰²(103-digit number)
38809739965400538537…17366570343943083521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.761 × 10¹⁰²(103-digit number)
77619479930801077074…34733140687886167041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.552 × 10¹⁰³(104-digit number)
15523895986160215414…69466281375772334081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.104 × 10¹⁰³(104-digit number)
31047791972320430829…38932562751544668161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.209 × 10¹⁰³(104-digit number)
62095583944640861659…77865125503089336321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.241 × 10¹⁰⁴(105-digit number)
12419116788928172331…55730251006178672641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.483 × 10¹⁰⁴(105-digit number)
24838233577856344663…11460502012357345281
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,603,050 XPM·at block #6,794,876 · updates every 60s
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