Block #601,861

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 6/25/2014, 8:57:38 PM · Difficulty 10.9139 · 6,194,965 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
ab4cf0d02d8a40580a62ca11201cf299997cdc4f0076f4c38f1f81395c79052d

Height

#601,861

Difficulty

10.913942

Transactions

4

Size

2.85 KB

Version

2

Bits

0ae9f81d

Nonce

431,814,438

Timestamp

6/25/2014, 8:57:38 PM

Confirmations

6,194,965

Merkle Root

3d4518976e37fdd004f1ead4cc87f7384c993ed079c3d105853107eba04ebacf
Transactions (4)
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.

1.320 × 10⁹⁸(99-digit number)
13201790580685247625…36250179112361963201
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
1.320 × 10⁹⁸(99-digit number)
13201790580685247625…36250179112361963201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.640 × 10⁹⁸(99-digit number)
26403581161370495250…72500358224723926401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.280 × 10⁹⁸(99-digit number)
52807162322740990500…45000716449447852801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.056 × 10⁹⁹(100-digit number)
10561432464548198100…90001432898895705601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.112 × 10⁹⁹(100-digit number)
21122864929096396200…80002865797791411201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.224 × 10⁹⁹(100-digit number)
42245729858192792400…60005731595582822401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.449 × 10⁹⁹(100-digit number)
84491459716385584801…20011463191165644801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.689 × 10¹⁰⁰(101-digit number)
16898291943277116960…40022926382331289601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.379 × 10¹⁰⁰(101-digit number)
33796583886554233920…80045852764662579201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.759 × 10¹⁰⁰(101-digit number)
67593167773108467841…60091705529325158401
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:57,618,618 XPM·at block #6,796,825 · updates every 60s
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