Block #446,596

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/16/2014, 4:35:35 PM · Difficulty 10.3593 · 6,359,374 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
04d30bb4f9768be7282dba3a3bf03ef6bbdf6d8fb4bed417377f4055b15660d0

Height

#446,596

Difficulty

10.359331

Transactions

4

Size

25.06 KB

Version

2

Bits

0a5bfd1d

Nonce

22,876

Timestamp

3/16/2014, 4:35:35 PM

Confirmations

6,359,374

Merkle Root

03e5737261e222dadcea3c36e2a681ae0b4be6b7e7a7d19214404a863ea4fe8b
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.

4.971 × 10¹⁰²(103-digit number)
49715131610440981550…38249856079860887041
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
4.971 × 10¹⁰²(103-digit number)
49715131610440981550…38249856079860887041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.943 × 10¹⁰²(103-digit number)
99430263220881963100…76499712159721774081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.988 × 10¹⁰³(104-digit number)
19886052644176392620…52999424319443548161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.977 × 10¹⁰³(104-digit number)
39772105288352785240…05998848638887096321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.954 × 10¹⁰³(104-digit number)
79544210576705570480…11997697277774192641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.590 × 10¹⁰⁴(105-digit number)
15908842115341114096…23995394555548385281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.181 × 10¹⁰⁴(105-digit number)
31817684230682228192…47990789111096770561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.363 × 10¹⁰⁴(105-digit number)
63635368461364456384…95981578222193541121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.272 × 10¹⁰⁵(106-digit number)
12727073692272891276…91963156444387082241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.545 × 10¹⁰⁵(106-digit number)
25454147384545782553…83926312888774164481
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:57,691,835 XPM·at block #6,805,969 · updates every 60s
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