Block #612,887

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 7/2/2014, 8:55:47 PM · Difficulty 10.9290 · 6,179,112 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
51bbc120469bb5d5ea58298e6b72bf9286df3f308d68e00d2bf02fcebfce00d2

Height

#612,887

Difficulty

10.929040

Transactions

4

Size

1.44 KB

Version

2

Bits

0aedd591

Nonce

41,972,139

Timestamp

7/2/2014, 8:55:47 PM

Confirmations

6,179,112

Merkle Root

31738fce8add3d56d41f6f612c3797dc82956f19fd72861e532dfc6512dc033c
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.

9.984 × 10⁹⁷(98-digit number)
99842987992053938885…94772882366679347199
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
9.984 × 10⁹⁷(98-digit number)
99842987992053938885…94772882366679347199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.996 × 10⁹⁸(99-digit number)
19968597598410787777…89545764733358694399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.993 × 10⁹⁸(99-digit number)
39937195196821575554…79091529466717388799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.987 × 10⁹⁸(99-digit number)
79874390393643151108…58183058933434777599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.597 × 10⁹⁹(100-digit number)
15974878078728630221…16366117866869555199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.194 × 10⁹⁹(100-digit number)
31949756157457260443…32732235733739110399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.389 × 10⁹⁹(100-digit number)
63899512314914520886…65464471467478220799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.277 × 10¹⁰⁰(101-digit number)
12779902462982904177…30928942934956441599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.555 × 10¹⁰⁰(101-digit number)
25559804925965808354…61857885869912883199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.111 × 10¹⁰⁰(101-digit number)
51119609851931616709…23715771739825766399
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:57,579,948 XPM·at block #6,791,998 · updates every 60s
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