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

0,2

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..1000

Example

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.

Prog

(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<m&&v[c+1]<0, v[c+1]=n)); for(j=1, m, print1(v[j], ", "))}
(Haskell)
import Data.List (elemIndex)
import Data.Maybe (fromJust)
a092954 = (+ 1) . fromJust . (`elemIndex` a092953_list)
-- Reinhard Zumkeller, Nov 10 2012

Crossrefs

Cf. A092953.

Sequence in context: A065970 A326890 A024463 * A114803 A083171 A058582

Adjacent sequences: A092951 A092952 A092953 * A092955 A092956 A092957

Keyword

nonn

Author

Amarnath Murthy, Mar 24 2004

Extensions

More terms from Klaus Brockhaus and Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 25 2004

Status

approved