Block #1,040,307

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 5/1/2015, 12:05:49 PM · Difficulty 10.7305 · 5,764,501 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
97a583be43cfa5718312338c60bcf87b1b4ee3829438a7086130e532138bfe4b

Height

#1,040,307

Difficulty

10.730520

Transactions

6

Size

1.59 KB

Version

2

Bits

0abb0361

Nonce

1,270,334,730

Timestamp

5/1/2015, 12:05:49 PM

Confirmations

5,764,501

Merkle Root

ec742fe27888606229a5065b69f3235e4b09dc3b3bd6cbf201e377753d854d07
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.

1.016 × 10⁹⁵(96-digit number)
10169843498718143162…48601298511246756799
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
1.016 × 10⁹⁵(96-digit number)
10169843498718143162…48601298511246756799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.033 × 10⁹⁵(96-digit number)
20339686997436286325…97202597022493513599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.067 × 10⁹⁵(96-digit number)
40679373994872572650…94405194044987027199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.135 × 10⁹⁵(96-digit number)
81358747989745145300…88810388089974054399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.627 × 10⁹⁶(97-digit number)
16271749597949029060…77620776179948108799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.254 × 10⁹⁶(97-digit number)
32543499195898058120…55241552359896217599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.508 × 10⁹⁶(97-digit number)
65086998391796116240…10483104719792435199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.301 × 10⁹⁷(98-digit number)
13017399678359223248…20966209439584870399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.603 × 10⁹⁷(98-digit number)
26034799356718446496…41932418879169740799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.206 × 10⁹⁷(98-digit number)
52069598713436892992…83864837758339481599
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 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
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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,682,532 XPM·at block #6,804,807 · updates every 60s
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