Block #785,577

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 10/27/2014, 4:52:16 PM · Difficulty 10.9750 · 6,018,002 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
4ae470cbdb2901d5ff14479dcbed1567f92b4f6afcf725b8d1d43ab83673441d

Height

#785,577

Difficulty

10.975031

Transactions

5

Size

1.20 KB

Version

2

Bits

0af99ba1

Nonce

360,339,217

Timestamp

10/27/2014, 4:52:16 PM

Confirmations

6,018,002

Merkle Root

d9a3c247cfff7e6aa11da2aa074db1978a7c7c2e7bc2a8da515ab6960ff9b740
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.

1.985 × 10⁹⁷(98-digit number)
19856020143871483257…61122539640491647999
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
1.985 × 10⁹⁷(98-digit number)
19856020143871483257…61122539640491647999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.971 × 10⁹⁷(98-digit number)
39712040287742966515…22245079280983295999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.942 × 10⁹⁷(98-digit number)
79424080575485933030…44490158561966591999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.588 × 10⁹⁸(99-digit number)
15884816115097186606…88980317123933183999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.176 × 10⁹⁸(99-digit number)
31769632230194373212…77960634247866367999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.353 × 10⁹⁸(99-digit number)
63539264460388746424…55921268495732735999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.270 × 10⁹⁹(100-digit number)
12707852892077749284…11842536991465471999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.541 × 10⁹⁹(100-digit number)
25415705784155498569…23685073982930943999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.083 × 10⁹⁹(100-digit number)
50831411568310997139…47370147965861887999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.016 × 10¹⁰⁰(101-digit number)
10166282313662199427…94740295931723775999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
2.033 × 10¹⁰⁰(101-digit number)
20332564627324398855…89480591863447551999
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:57,672,667 XPM·at block #6,803,578 · updates every 60s
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