Block #159,827

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 9/11/2013, 10:56:48 AM · Difficulty 9.8632 · 6,642,804 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d7da6e77c2eff247f74d72af7e77e32c9a7b94f2621d6a717c5a6a845cab8e75

Height

#159,827

Difficulty

9.863167

Transactions

9

Size

3.41 KB

Version

2

Bits

09dcf880

Nonce

283

Timestamp

9/11/2013, 10:56:48 AM

Confirmations

6,642,804

Merkle Root

6ce0b0bb4daaf7675d20fcd357471b179c4275003771dd620451bd64444142ad
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.

2.304 × 10⁹⁵(96-digit number)
23043345702251533985…14013910859890124319
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
2.304 × 10⁹⁵(96-digit number)
23043345702251533985…14013910859890124319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.608 × 10⁹⁵(96-digit number)
46086691404503067971…28027821719780248639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
9.217 × 10⁹⁵(96-digit number)
92173382809006135943…56055643439560497279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.843 × 10⁹⁶(97-digit number)
18434676561801227188…12111286879120994559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.686 × 10⁹⁶(97-digit number)
36869353123602454377…24222573758241989119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.373 × 10⁹⁶(97-digit number)
73738706247204908755…48445147516483978239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.474 × 10⁹⁷(98-digit number)
14747741249440981751…96890295032967956479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.949 × 10⁹⁷(98-digit number)
29495482498881963502…93780590065935912959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.899 × 10⁹⁷(98-digit number)
58990964997763927004…87561180131871825919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.179 × 10⁹⁸(99-digit number)
11798192999552785400…75122360263743651839
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:57,665,063 XPM·at block #6,802,630 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.