Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #9 Nov 21 2013 12:49:59
%S 2,7,18,35,58,87,128,175,228,287,358,441,530,631,738,851,982,1119,
%T 1268,1435,1608,1787,1978,2175,2402,2635,2874,3125,3382,3645,3914,
%U 4195,4488,4799,5116,5463,5816,6175,6558,6947,7348,7767,8198,8641,9090,9551,10018
%N Partial sums of primes of the form 3*k-1.
%e a(1)=3*1-1=2, a(2)=2+3*2-1=7.
%p Contribution from _R. J. Mathar_, Apr 24 2010: (Start)
%p A003627 := proc(n) if n <= 2 then op(n,[2,5]) ; else for a from procname(n-1)+2 by 2 do if isprime(a) and (a mod 3) =2 then return a ; end if; end do: end if; end proc:
%p A172188 := proc(n) add( A003627(i),i=1..n) ; end proc: seq(A172188(n),n=1..80) ; (End)
%t Accumulate[Select[Prime[Range[100]],IntegerQ[(#+1)/3]&]] (* _Harvey P. Dale_, Apr 04 2011 *)
%Y Cf. A038361.
%K nonn
%O 1,1
%A _Juri-Stepan Gerasimov_, Jan 29 2010, Feb 01 2010
%E Entries checked by _R. J. Mathar_, Apr 24 2010