Block #354,150

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/11/2014, 9:15:58 AM · Difficulty 10.3372 · 6,453,650 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d4e12b251d83508106a8b9ad751e95368e80a77b13e895a4e6294107ca62d775

Height

#354,150

Difficulty

10.337230

Transactions

5

Size

2.72 KB

Version

2

Bits

0a5654ad

Nonce

41,823

Timestamp

1/11/2014, 9:15:58 AM

Confirmations

6,453,650

Merkle Root

b8d1ef918b2be4a965dd4f11593d1966f91a29faec4f77d007d864962a215b36
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.

3.520 × 10¹⁰³(104-digit number)
35200300175363888323…67028084482501689281
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
3.520 × 10¹⁰³(104-digit number)
35200300175363888323…67028084482501689281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
7.040 × 10¹⁰³(104-digit number)
70400600350727776646…34056168965003378561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.408 × 10¹⁰⁴(105-digit number)
14080120070145555329…68112337930006757121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.816 × 10¹⁰⁴(105-digit number)
28160240140291110658…36224675860013514241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.632 × 10¹⁰⁴(105-digit number)
56320480280582221317…72449351720027028481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.126 × 10¹⁰⁵(106-digit number)
11264096056116444263…44898703440054056961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.252 × 10¹⁰⁵(106-digit number)
22528192112232888526…89797406880108113921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.505 × 10¹⁰⁵(106-digit number)
45056384224465777053…79594813760216227841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
9.011 × 10¹⁰⁵(106-digit number)
90112768448931554107…59189627520432455681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.802 × 10¹⁰⁶(107-digit number)
18022553689786310821…18379255040864911361
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 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
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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,706,433 XPM·at block #6,807,799 · updates every 60s
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