Block #330,064

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/26/2013, 10:06:22 AM · Difficulty 10.1684 · 6,475,739 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
cfa2609ac632697ffb393d3976e1aed9d1404d937c4f5cc7f1365458624adec9

Height

#330,064

Difficulty

10.168433

Transactions

21

Size

15.22 KB

Version

2

Bits

0a2b1e73

Nonce

77,253

Timestamp

12/26/2013, 10:06:22 AM

Confirmations

6,475,739

Merkle Root

72eea50a8a4b2e041214f66690b8d80c3e6668b9dd337d2c59c961175770fdff
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.

1.998 × 10⁹⁶(97-digit number)
19989045678394465965…71959660170241726399
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
1.998 × 10⁹⁶(97-digit number)
19989045678394465965…71959660170241726399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.997 × 10⁹⁶(97-digit number)
39978091356788931930…43919320340483452799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.995 × 10⁹⁶(97-digit number)
79956182713577863860…87838640680966905599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.599 × 10⁹⁷(98-digit number)
15991236542715572772…75677281361933811199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.198 × 10⁹⁷(98-digit number)
31982473085431145544…51354562723867622399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.396 × 10⁹⁷(98-digit number)
63964946170862291088…02709125447735244799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.279 × 10⁹⁸(99-digit number)
12792989234172458217…05418250895470489599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.558 × 10⁹⁸(99-digit number)
25585978468344916435…10836501790940979199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.117 × 10⁹⁸(99-digit number)
51171956936689832870…21673003581881958399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.023 × 10⁹⁹(100-digit number)
10234391387337966574…43346007163763916799
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:57,690,509 XPM·at block #6,805,802 · updates every 60s
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