A092954 Index of the first occurrence of n in A092953. There are a(n) primes p < n such that n+p is a prime.
1, 3, 8, 12, 26, 40, 24, 48, 42, 54, 110, 60, 140, 84, 160, 90, 132, 126, 162, 120, 168, 216, 204, 222, 246, 180, 264, 252, 240, 210, 366, 342, 270, 396, 300, 414, 336, 516, 850, 558, 330, 462, 534, 552, 390, 504, 450, 1040, 540, 588, 420, 594, 708, 510, 876
Offset: 0
Keywords
Examples
a(6) = 24 as there are 6 values the prime p can take, 5, 7, 13, 17, 19 and 23 < 24 so that 24 + p is also prime.
Links
- Reinhard Zumkeller, Table of n, a(n) for n = 0..1000
Crossrefs
Cf. A092953.
Programs
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Haskell
import Data.List (elemIndex) import Data.Maybe (fromJust) a092954 = (+ 1) . fromJust . (`elemIndex` a092953_list) -- Reinhard Zumkeller, Nov 10 2012
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PARI
{stop=1050;m=56;v=vector(m,x,-1);for(n=1,stop,c=0;forprime(p=2,n-1,if(isprime(n+p),c++)); if(c
Extensions
More terms from Klaus Brockhaus and Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 25 2004