Block #336,886

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/31/2013, 6:58:48 AM · Difficulty 10.1396 · 6,475,859 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
f2f4eec95bc882f9b8dc63f060ed8def52299ea7b60e462e9a5296f1da09bf03

Height

#336,886

Difficulty

10.139583

Transactions

10

Size

3.29 KB

Version

2

Bits

0a23bbaf

Nonce

38,196

Timestamp

12/31/2013, 6:58:48 AM

Confirmations

6,475,859

Merkle Root

fdcada18689b89071f54660707f9bed0edf8f9ce37ca1a487fe85edaf87b38f9
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.

2.050 × 10¹⁰⁰(101-digit number)
20508002343416032048…69627063738009075799
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
2.050 × 10¹⁰⁰(101-digit number)
20508002343416032048…69627063738009075799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.101 × 10¹⁰⁰(101-digit number)
41016004686832064097…39254127476018151599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.203 × 10¹⁰⁰(101-digit number)
82032009373664128194…78508254952036303199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.640 × 10¹⁰¹(102-digit number)
16406401874732825638…57016509904072606399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.281 × 10¹⁰¹(102-digit number)
32812803749465651277…14033019808145212799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.562 × 10¹⁰¹(102-digit number)
65625607498931302555…28066039616290425599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.312 × 10¹⁰²(103-digit number)
13125121499786260511…56132079232580851199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.625 × 10¹⁰²(103-digit number)
26250242999572521022…12264158465161702399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.250 × 10¹⁰²(103-digit number)
52500485999145042044…24528316930323404799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.050 × 10¹⁰³(104-digit number)
10500097199829008408…49056633860646809599
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:57,746,003 XPM·at block #6,812,744 · updates every 60s
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