Block #110,384

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/10/2013, 10:28:16 PM · Difficulty 9.6906 · 6,682,043 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
28b737d7a60e9711a19f3e55704911d86dc2695d6b52d2d6d0564053bc7d2a7b

Height

#110,384

Difficulty

9.690615

Transactions

2

Size

620 B

Version

2

Bits

09b0cc1e

Nonce

642,059

Timestamp

8/10/2013, 10:28:16 PM

Confirmations

6,682,043

Merkle Root

01dbddb8e0fd71de384605e100f6096c8151bf81300194ec765ef3eff8c02baa
Transactions (2)
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.

2.112 × 10⁹⁶(97-digit number)
21127776819735042084…62098448622451861759
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
2.112 × 10⁹⁶(97-digit number)
21127776819735042084…62098448622451861759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.225 × 10⁹⁶(97-digit number)
42255553639470084168…24196897244903723519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.451 × 10⁹⁶(97-digit number)
84511107278940168337…48393794489807447039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.690 × 10⁹⁷(98-digit number)
16902221455788033667…96787588979614894079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.380 × 10⁹⁷(98-digit number)
33804442911576067334…93575177959229788159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.760 × 10⁹⁷(98-digit number)
67608885823152134669…87150355918459576319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.352 × 10⁹⁸(99-digit number)
13521777164630426933…74300711836919152639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.704 × 10⁹⁸(99-digit number)
27043554329260853867…48601423673838305279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.408 × 10⁹⁸(99-digit number)
54087108658521707735…97202847347676610559
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,583,373 XPM·at block #6,792,426 · updates every 60s
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