A171562 Numbers k such that the k-th non-single or nonisolated number is prime.

1, 6, 8, 10, 11, 13, 15, 16, 17, 18, 21, 22, 23, 26, 27, 28, 29, 33, 34, 36, 38, 39, 40, 42, 44, 45, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 63, 64, 65, 66, 68, 69, 70, 71, 72, 73, 74, 76, 77, 78, 79, 81, 82, 83, 85, 86, 88, 90, 91, 93, 94, 95, 96, 97, 98, 99, 100

Offset

1,2

Links

Table of n, a(n) for n=1..70.

Maple

A167706 := proc(n) if n = 1 then 2; else for a from procname(n-1)+1 do if isA007510(a) or isA014574(a) then return a; end if; end do; end if; end proc:
for n from 1 to 110 do p := A167706(n) ; if isprime(p) then printf("%d, ", n) : end if; end do: # R. J. Mathar, May 23 2010

Crossrefs

Cf. A000040 (the prime numbers), A167706 (the single or isolated numbers).

Sequence in context: A315849 A138890 A189082 * A018221 A071278 A079772

Adjacent sequences: A171559 A171560 A171561 * A171563 A171564 A171565

Keyword

nonn

Author

Juri-Stepan Gerasimov, Dec 11 2009

Extensions

Corrected (20 replaced with 18, 25 replaced with 23, 32 replaced with 29, etc.) by R. J. Mathar, May 23 2010

Status

approved