Block #452,837

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/20/2014, 8:41:35 PM · Difficulty 10.3923 · 6,352,910 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
16bd0d196fb99f4f694c17514fb7b4273c925c09305929dac3ab6851c6e9c554

Height

#452,837

Difficulty

10.392287

Transactions

6

Size

1.30 KB

Version

2

Bits

0a646ceb

Nonce

21,096,351

Timestamp

3/20/2014, 8:41:35 PM

Confirmations

6,352,910

Merkle Root

9c54838d56d3959f1c816ddc9a1796a88a0680d6ed52bb16d99992f2081e3aea
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.

1.643 × 10⁹³(94-digit number)
16439380779947752539…49815635355953978261
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
1.643 × 10⁹³(94-digit number)
16439380779947752539…49815635355953978261
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.287 × 10⁹³(94-digit number)
32878761559895505079…99631270711907956521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.575 × 10⁹³(94-digit number)
65757523119791010159…99262541423815913041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.315 × 10⁹⁴(95-digit number)
13151504623958202031…98525082847631826081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.630 × 10⁹⁴(95-digit number)
26303009247916404063…97050165695263652161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.260 × 10⁹⁴(95-digit number)
52606018495832808127…94100331390527304321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.052 × 10⁹⁵(96-digit number)
10521203699166561625…88200662781054608641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.104 × 10⁹⁵(96-digit number)
21042407398333123250…76401325562109217281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.208 × 10⁹⁵(96-digit number)
42084814796666246501…52802651124218434561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.416 × 10⁹⁵(96-digit number)
84169629593332493003…05605302248436869121
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:57,690,057 XPM·at block #6,805,746 · updates every 60s
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