Block #327,339

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/24/2013, 11:52:51 AM · Difficulty 10.1756 · 6,467,423 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
2bf8ef7f7ae1d2169cb06f6365dbfbc90be835771748b162606d7ce66a8e7eff

Height

#327,339

Difficulty

10.175551

Transactions

8

Size

2.43 KB

Version

2

Bits

0a2cf0e3

Nonce

2,258

Timestamp

12/24/2013, 11:52:51 AM

Confirmations

6,467,423

Merkle Root

9f14ed89b3dbabd44830d15e7e6ea3b4eff899480264a7375fd59aa4224b88c5
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.

7.728 × 10¹⁰²(103-digit number)
77280037143323711883…04812051697075999679
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
7.728 × 10¹⁰²(103-digit number)
77280037143323711883…04812051697075999679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.545 × 10¹⁰³(104-digit number)
15456007428664742376…09624103394151999359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.091 × 10¹⁰³(104-digit number)
30912014857329484753…19248206788303998719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.182 × 10¹⁰³(104-digit number)
61824029714658969506…38496413576607997439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.236 × 10¹⁰⁴(105-digit number)
12364805942931793901…76992827153215994879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.472 × 10¹⁰⁴(105-digit number)
24729611885863587802…53985654306431989759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.945 × 10¹⁰⁴(105-digit number)
49459223771727175605…07971308612863979519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
9.891 × 10¹⁰⁴(105-digit number)
98918447543454351210…15942617225727959039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.978 × 10¹⁰⁵(106-digit number)
19783689508690870242…31885234451455918079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.956 × 10¹⁰⁵(106-digit number)
39567379017381740484…63770468902911836159
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:57,602,144 XPM·at block #6,794,761 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.