A275988 a(n) = prime(3n) - prime(n).

3, 10, 18, 30, 36, 48, 56, 70, 80, 84, 106, 114, 126, 138, 150, 170, 174, 190, 202, 210, 234, 238, 264, 270, 282, 296, 316, 326, 340, 350, 360, 372, 386, 418, 422, 442, 450, 456, 476, 486, 498, 520, 536, 550, 564, 588, 600, 604, 626, 634, 650, 672, 696, 702, 720, 734, 750, 762, 774

Offset

1,1

Links

Table of n, a(n) for n=1..59.

Formula

a(n) = A031336(n) - A000040(n).

Example

For n=3, prime(3n) = 23, and prime(n) = 5, therefore a(3) = 23 - 5 = 18.

Mathematica

Table[Prime[3n] - Prime[n], {n, 1, 100}]

Prog

(PARI) a(n) = prime(3*n) - prime(n); \\ Michel Marcus, Aug 18 2016

Crossrefs

Cf. A000040, A031336, A072473.

Sequence in context: A051938 A171834 A210286 * A177955 A298976 A265487

Adjacent sequences: A275985 A275986 A275987 * A275989 A275990 A275991

Keyword

nonn

Author

Terry D. Grant, Aug 15 2016

Status

approved