A104493 Numbers n for which the cube excess of the n-th prime is prime.

2, 5, 6, 8, 10, 19, 20, 23, 26, 28, 31, 48, 49, 50, 51, 52, 55, 56, 57, 59, 61, 65, 66, 99, 100, 105, 110, 112, 114, 117, 121, 125, 127, 170, 171, 173, 178, 184, 185, 186, 190, 192, 194, 196, 200, 201, 206, 208, 214, 270, 271, 272, 274, 277, 278, 279, 280, 282

Offset

1,1

Links

Table of n, a(n) for n=1..58.

Formula

n such that A055400(A000040(n)) is an element of A000040. n such that A104492(n) is prime.

Example

99 is an element of this sequence because the 99th prime is 523, 523 - 8^3 = 523-512 = 11 and 11 is prime. 100 is in this sequence because the 100th prime is 541 and 541-8^3 = 29, which is prime.

Mathematica

f[n_] := Block[{k = 1, p = Prime[n]}, While[k^3 < p, k++ ]; p - (k - 1)^3]; Select[ Range[ 284], PrimeQ[ f[ # ]] &] (* Robert G. Wilson v, Mar 19 2005 *)

Crossrefs

Cf. A000040, A053186, A055400, A056892, A102821, A104492.

Sequence in context: A081083 A288635 A308595 * A139532 A024798 A108857

Adjacent sequences: A104490 A104491 A104492 * A104494 A104495 A104496

Keyword

easy,nonn

Author

Jonathan Vos Post, Mar 19 2005

Extensions

More terms from Robert G. Wilson v, Mar 19 2005

Status

approved