Block #979,852

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 3/18/2015, 11:58:53 AM · Difficulty 10.8473 · 5,836,459 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
deed212bb78c80fb4380b11f0646ae02792507d033f5c95dd938899274fb5765

Height

#979,852

Difficulty

10.847254

Transactions

17

Size

22.92 KB

Version

2

Bits

0ad8e59d

Nonce

134,725,316

Timestamp

3/18/2015, 11:58:53 AM

Confirmations

5,836,459

Merkle Root

a845e6ca46b6cd694eff63c6da6d6c54c34f337dafa99af832b6c46c68617396
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.

8.251 × 10⁹⁵(96-digit number)
82519017414070990022…74814486468523860961
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
8.251 × 10⁹⁵(96-digit number)
82519017414070990022…74814486468523860961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.650 × 10⁹⁶(97-digit number)
16503803482814198004…49628972937047721921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.300 × 10⁹⁶(97-digit number)
33007606965628396009…99257945874095443841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.601 × 10⁹⁶(97-digit number)
66015213931256792018…98515891748190887681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.320 × 10⁹⁷(98-digit number)
13203042786251358403…97031783496381775361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.640 × 10⁹⁷(98-digit number)
26406085572502716807…94063566992763550721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.281 × 10⁹⁷(98-digit number)
52812171145005433614…88127133985527101441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.056 × 10⁹⁸(99-digit number)
10562434229001086722…76254267971054202881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.112 × 10⁹⁸(99-digit number)
21124868458002173445…52508535942108405761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.224 × 10⁹⁸(99-digit number)
42249736916004346891…05017071884216811521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
8.449 × 10⁹⁸(99-digit number)
84499473832008693783…10034143768433623041
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 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
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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,774,609 XPM·at block #6,816,310 · updates every 60s
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