A118482 Partial sums of Chen primes (starting with 1).

1, 3, 6, 11, 18, 29, 42, 59, 78, 101, 130, 161, 198, 239, 286, 339, 398, 465, 536, 619, 708, 809, 916, 1025, 1138, 1265, 1396, 1533, 1672, 1821, 1978, 2145, 2324, 2505, 2696, 2893, 3092, 3303, 3530, 3763, 4002, 4253, 4510, 4773, 5042, 5323, 5616, 5923

Offset

0,2

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Maple

ischenprime:=proc(n); if (isprime(n) = 'true') then if (isprime(n+2) = 'true' or numtheory[bigomega](n+2) = 2) then RETURN('true') else RETURN('false') fi fi end: ts_partsum_chenprime:=proc(n) local i, ans, tren; ans:=1: tren:=1: for i from 1 to n do if (ischenprime(i)='true') then tren := tren+i: ans:=[op(ans), tren]: fi od; RETURN(ans) end: ts_partsum_chenprime(500);

Mathematica

Accumulate[Join[{1}, Select[Prime[Range[70]], PrimeOmega[#+2]<3&]]] (* Harvey P. Dale, May 26 2014 *)

Crossrefs

Cf. A014284, A109611.

Sequence in context: A178855 A095944 A014284 * A281689 A026905 A286272

Adjacent sequences: A118479 A118480 A118481 * A118483 A118484 A118485

Keyword

nonn

Author

Jani Melik, May 05 2006

Status

approved