Block #1,459,274

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 2/16/2016, 5:03:47 AM · Difficulty 10.7715 · 5,374,672 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
075d0004a305af1d89d29522ee2b28f212a4784b3d814fca5620b79c20a8e5ea

Height

#1,459,274

Difficulty

10.771459

Transactions

2

Size

798 B

Version

2

Bits

0ac57e4f

Nonce

333,266,047

Timestamp

2/16/2016, 5:03:47 AM

Confirmations

5,374,672

Merkle Root

b364d6083a73afb9890bf11aecc8d1768a17cdd7e1fb2df9117e4ecae6ac4fec
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.

1.534 × 10⁹⁵(96-digit number)
15347800016066295627…15912605177142333761
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
1.534 × 10⁹⁵(96-digit number)
15347800016066295627…15912605177142333761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.069 × 10⁹⁵(96-digit number)
30695600032132591255…31825210354284667521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.139 × 10⁹⁵(96-digit number)
61391200064265182511…63650420708569335041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.227 × 10⁹⁶(97-digit number)
12278240012853036502…27300841417138670081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.455 × 10⁹⁶(97-digit number)
24556480025706073004…54601682834277340161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.911 × 10⁹⁶(97-digit number)
49112960051412146008…09203365668554680321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.822 × 10⁹⁶(97-digit number)
98225920102824292017…18406731337109360641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.964 × 10⁹⁷(98-digit number)
19645184020564858403…36813462674218721281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.929 × 10⁹⁷(98-digit number)
39290368041129716807…73626925348437442561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.858 × 10⁹⁷(98-digit number)
78580736082259433614…47253850696874885121
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:57,915,796 XPM·at block #6,833,945 · updates every 60s
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