Block #384,621

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 2/1/2014, 6:12:06 AM · Difficulty 10.4001 · 6,411,291 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
6a13b659be1262398b6fa43aa627eaba86b2a025dcc1bae47a4e7baadd74a251

Height

#384,621

Difficulty

10.400081

Transactions

2

Size

436 B

Version

2

Bits

0a666bad

Nonce

290

Timestamp

2/1/2014, 6:12:06 AM

Confirmations

6,411,291

Merkle Root

8a5bf4298c2c5b251597a744b7d7fd0dc99cf511ad8c990d37f9803affa85d2f
Transactions (2)
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.

1.455 × 10¹⁰²(103-digit number)
14554427834232655731…70443134898174689279
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
1.455 × 10¹⁰²(103-digit number)
14554427834232655731…70443134898174689279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.910 × 10¹⁰²(103-digit number)
29108855668465311462…40886269796349378559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.821 × 10¹⁰²(103-digit number)
58217711336930622925…81772539592698757119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.164 × 10¹⁰³(104-digit number)
11643542267386124585…63545079185397514239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.328 × 10¹⁰³(104-digit number)
23287084534772249170…27090158370795028479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.657 × 10¹⁰³(104-digit number)
46574169069544498340…54180316741590056959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.314 × 10¹⁰³(104-digit number)
93148338139088996681…08360633483180113919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.862 × 10¹⁰⁴(105-digit number)
18629667627817799336…16721266966360227839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.725 × 10¹⁰⁴(105-digit number)
37259335255635598672…33442533932720455679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.451 × 10¹⁰⁴(105-digit number)
74518670511271197345…66885067865440911359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
1.490 × 10¹⁰⁵(106-digit number)
14903734102254239469…33770135730881822719
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:57,611,381 XPM·at block #6,795,911 · 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.