cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A092954 Index of the first occurrence of n in A092953. There are a(n) primes p < n such that n+p is a prime.

Original entry on oeis.org

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

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Author

Amarnath Murthy, Mar 24 2004

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.
		

Crossrefs

Cf. A092953.

Programs

  • Haskell
    import Data.List (elemIndex)
    import Data.Maybe (fromJust)
    a092954 = (+ 1) . fromJust . (`elemIndex` a092953_list)
    -- Reinhard Zumkeller, Nov 10 2012
  • 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