Home/Chain Registry/Block #85,020

Block #85,020

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 7/27/2013, 4:38:36 AM · Difficulty 9.2822 · 6,706,719 confirmations

TWN
Bi-Twin Chain

Interleaved pairs of primes that differ by 2, forming twin prime pairs at each level.

Block Header
Block Hash
aaf0959f5473b0c135ded8721c75ee1c1b2bf38ddfb210345073d1b09a85a3ba

Height

#85,020

Difficulty

9.282168

Transactions

6

Size

1.10 KB

Version

2

Bits

09483c27

Nonce

20,410

Timestamp

7/27/2013, 4:38:36 AM

Confirmations

6,706,719

Merkle Root

27b78801e0b951e223346a482f71ea969f14bbc94ad0cbeb7fc8e2d9b3683692
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.

6.597 × 10⁹⁷(98-digit number)
65971953708463395022…29646956447545414070
Discovered Prime Numbers
Lower: 2^k × origin − 1 | Upper: 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.

Level 0 — Twin Prime Pair (origin ± 1)
origin − 1
6.597 × 10⁹⁷(98-digit number)
65971953708463395022…29646956447545414069
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
6.597 × 10⁹⁷(98-digit number)
65971953708463395022…29646956447545414071
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: origin + 1 − origin − 1 = 2 (twin primes ✓)
Level 1 — Twin Prime Pair (2^1 × origin ± 1)
2^1 × origin − 1
1.319 × 10⁹⁸(99-digit number)
13194390741692679004…59293912895090828139
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.319 × 10⁹⁸(99-digit number)
13194390741692679004…59293912895090828141
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^1 × origin + 1 − 2^1 × origin − 1 = 2 (twin primes ✓)
Level 2 — Twin Prime Pair (2^2 × origin ± 1)
2^2 × origin − 1
2.638 × 10⁹⁸(99-digit number)
26388781483385358008…18587825790181656279
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.638 × 10⁹⁸(99-digit number)
26388781483385358008…18587825790181656281
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^2 × origin + 1 − 2^2 × origin − 1 = 2 (twin primes ✓)
Level 3 — Twin Prime Pair (2^3 × origin ± 1)
2^3 × origin − 1
5.277 × 10⁹⁸(99-digit number)
52777562966770716017…37175651580363312559
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
5.277 × 10⁹⁸(99-digit number)
52777562966770716017…37175651580363312561
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^3 × origin + 1 − 2^3 × origin − 1 = 2 (twin primes ✓)
Level 4 — Twin Prime Pair (2^4 × origin ± 1)
2^4 × origin − 1
1.055 × 10⁹⁹(100-digit number)
10555512593354143203…74351303160726625119
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 Bi-Twin Chain. 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.

View full Prime Chain Discovery page →
★☆☆☆☆
Rarity
CommonChain length 9
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 TWN formula:

TWN: twin pairs (p, p+2) where p = origin/primorial − 1 and p+2 = origin/primorial + 1
Verify on a Primecoin Node

Anyone running a Primecoin node can independently verify this block using the following RPC commands. Run these from the primecoin-cli command line or via the debug console in the Primecoin wallet.

1. Get block hash by height
getblockhash 85020

Returns the block hash for a given block height. Use this to confirm the hash shown above matches the chain.

2. Get full block data
getblock aaf0959f5473b0c135ded8721c75ee1c1b2bf38ddfb210345073d1b09a85a3ba

Returns the full block header including difficulty, prime chain origin, prime chain type, transaction IDs, and all other fields shown on this page.

How to run these commands: To verify this data independently, open a terminal on your own Primecoin node and run primecoin-cli <command>. Alternatively, open the Primecoin-Qt wallet, go to Help → Debug Window → Console, and type the command directly. The node must be fully synced to this block height for the commands to return results.

Cross-reference on Chainz Explorer

Chainz is an independent Primecoin block explorer. Compare this block's data to verify accuracy.

View Block #85,020 on Chainz ↗
Circulating Supply:57,577,863 XPM·at block #6,791,738 · updates every 60s
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