Block #2,234,671

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 8/3/2017, 4:50:50 AM · Difficulty 10.9457 · 4,604,006 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
f4f7dd1f0dd7e2dd00dd0dac768eecf87b2aadd178635818de2045b25ece2f09

Height

#2,234,671

Difficulty

10.945725

Transactions

3

Size

1.22 KB

Version

2

Bits

0af21b0d

Nonce

430,852,403

Timestamp

8/3/2017, 4:50:50 AM

Confirmations

4,604,006

Merkle Root

809040b3486927b26dfe395c1f1f82eccd0bb67cd99967f31988b8c89a4e0d91
Transactions (3)
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.

7.774 × 10⁹⁵(96-digit number)
77745561580485443202…65461767909377658879
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
7.774 × 10⁹⁵(96-digit number)
77745561580485443202…65461767909377658879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.554 × 10⁹⁶(97-digit number)
15549112316097088640…30923535818755317759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.109 × 10⁹⁶(97-digit number)
31098224632194177280…61847071637510635519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.219 × 10⁹⁶(97-digit number)
62196449264388354561…23694143275021271039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.243 × 10⁹⁷(98-digit number)
12439289852877670912…47388286550042542079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.487 × 10⁹⁷(98-digit number)
24878579705755341824…94776573100085084159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.975 × 10⁹⁷(98-digit number)
49757159411510683649…89553146200170168319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
9.951 × 10⁹⁷(98-digit number)
99514318823021367299…79106292400340336639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.990 × 10⁹⁸(99-digit number)
19902863764604273459…58212584800680673279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.980 × 10⁹⁸(99-digit number)
39805727529208546919…16425169601361346559
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:57,953,677 XPM·at block #6,838,676 · updates every 60s
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