A163654 The sum of the n-th and (n+1)st isolated prime.

25, 60, 84, 100, 120, 146, 162, 172, 186, 210, 240, 258, 288, 320, 330, 340, 384, 434, 456, 484, 508, 520, 540, 570, 600, 624, 648, 668, 690, 712, 726, 740, 752, 762, 772, 786, 798, 810, 848, 882, 892, 906, 924, 946, 966, 978, 990, 1002, 1012, 1050, 1088, 1104, 1120

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Formula

a(n) = A007510(n) + A007510(n+1).

Example

a(1) = 25 = 2+23.

Mathematica

A007510 := Select[Prime[Range[4, 2000]], ! PrimeQ[# - 2] && ! PrimeQ[# + 2] &]; Join[{25}, Table[A007510[[n]] + A007510[[n + 1]], {n, 1, 50}]] (* G. C. Greubel, Aug 01 2017 *)

Crossrefs

Cf. A007510.

Sequence in context: A266817 A125827 A250191 * A063317 A241505 A090820

Adjacent sequences: A163651 A163652 A163653 * A163655 A163656 A163657

Keyword

nonn

Author

Juri-Stepan Gerasimov, Aug 02 2009

Extensions

330 inserted by R. J. Mathar, Aug 06 2009

Status

approved