Block #748,192

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 10/1/2014, 2:56:42 AM · Difficulty 10.9780 · 6,053,621 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
dbde373148d3030863ceebef4050325af207e6e2b0758669f88083699510ec9f

Height

#748,192

Difficulty

10.978044

Transactions

2

Size

2.30 KB

Version

2

Bits

0afa6118

Nonce

23,309,331

Timestamp

10/1/2014, 2:56:42 AM

Confirmations

6,053,621

Merkle Root

0147311e0268f113aa5185eef7d57df3f435554e22d3f5d881fd48a253180020
Transactions (2)
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.

6.375 × 10⁹⁷(98-digit number)
63755199015574861018…36653200814657064959
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
6.375 × 10⁹⁷(98-digit number)
63755199015574861018…36653200814657064959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.275 × 10⁹⁸(99-digit number)
12751039803114972203…73306401629314129919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.550 × 10⁹⁸(99-digit number)
25502079606229944407…46612803258628259839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.100 × 10⁹⁸(99-digit number)
51004159212459888815…93225606517256519679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.020 × 10⁹⁹(100-digit number)
10200831842491977763…86451213034513039359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.040 × 10⁹⁹(100-digit number)
20401663684983955526…72902426069026078719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.080 × 10⁹⁹(100-digit number)
40803327369967911052…45804852138052157439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.160 × 10⁹⁹(100-digit number)
81606654739935822104…91609704276104314879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.632 × 10¹⁰⁰(101-digit number)
16321330947987164420…83219408552208629759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.264 × 10¹⁰⁰(101-digit number)
32642661895974328841…66438817104417259519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
6.528 × 10¹⁰⁰(101-digit number)
65285323791948657683…32877634208834519039
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 consecutive prime numbers forming a Cunningham Chain of the First 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,658,596 XPM·at block #6,801,812 · updates every 60s
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