Block #452,835

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/20/2014, 8:35:11 PM · Difficulty 10.3923 · 6,351,209 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7e4a32f6f4c7dcf7278abe5fb61a0ce11f9de9b75a7f3c05799f0ec7ca798e35

Height

#452,835

Difficulty

10.392327

Transactions

3

Size

1.79 KB

Version

2

Bits

0a646f8b

Nonce

30,982

Timestamp

3/20/2014, 8:35:11 PM

Confirmations

6,351,209

Merkle Root

ac4358dd2f9a2ea13a0fef83571c5878ec4d26c6d3fd75394a1410a8c7b8728f
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.

6.015 × 10¹⁰⁰(101-digit number)
60157248125813658023…42382623555687270401
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
6.015 × 10¹⁰⁰(101-digit number)
60157248125813658023…42382623555687270401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.203 × 10¹⁰¹(102-digit number)
12031449625162731604…84765247111374540801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.406 × 10¹⁰¹(102-digit number)
24062899250325463209…69530494222749081601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.812 × 10¹⁰¹(102-digit number)
48125798500650926418…39060988445498163201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
9.625 × 10¹⁰¹(102-digit number)
96251597001301852837…78121976890996326401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.925 × 10¹⁰²(103-digit number)
19250319400260370567…56243953781992652801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.850 × 10¹⁰²(103-digit number)
38500638800520741134…12487907563985305601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.700 × 10¹⁰²(103-digit number)
77001277601041482269…24975815127970611201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.540 × 10¹⁰³(104-digit number)
15400255520208296453…49951630255941222401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.080 × 10¹⁰³(104-digit number)
30800511040416592907…99903260511882444801
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:57,676,405 XPM·at block #6,804,043 · updates every 60s
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