This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A154588 #14 Feb 08 2024 12:22:06
%S A154588 1,28,435,10296,415416,1062153,3703281,426626655,782002378,
%T A154588 102886232631,1636197988776,2749764593278,61972139524851,
%U A154588 813577626225078,1604393353172781,3603538956517305,44000970048906445,83556903098276790,208955344344897381
%N A154588 Numbers that can be expressed as the sum of the first j integer numbers or the first k nonprime numbers, with j and k >=1.
%C A154588 The indices (j,k) where A000217(j) = A051349(k) are (1,1), (7,5), (29,23), (143,123), (911,823), (1457,1327), (2721,2501), (29210,27488), (39547,37295) , (453621,433381) , (1808976,1737137) , (2345107,2253859) , (11133026,10746793), (40338012,39053670), (56646153,54880858) , (84894510,82314170) , (296651209,288273745), (408795555,397457085), (646460121,628975505). - _Donovan Johnson_, Sep 11 2009
%F A154588 (A000217 INTERSECT A051349) MINUS {0}. - _R. J. Mathar_, Jan 21 2009
%e A154588 28 = A000217(7) = A051349(5).
%e A154588 435 = A000217(19) = A051349(23).
%e A154588 10296 = A000217(143) = A051349(123).
%t A154588 Module[{nn=10^7,np},np=Select[Range[nn],!PrimeQ[#]&];Intersection[Accumulate[Range[ nn]],Accumulate[ np]]] (* The program generates the first 12 terms of the sequence. *) (* _Harvey P. Dale_, Feb 08 2024 *)
%Y A154588 Cf. A007504, A051349, A066527, A133784, A154587.
%K A154588 nonn
%O A154588 1,2
%A A154588 _Paolo P. Lava_ & _Giorgio Balzarotti_, Jan 16 2009, Jan 19 2009
%E A154588 10256 replaced with 10296 and two more terms added by _R. J. Mathar_, Jan 21 2009
%E A154588 Extended beyond a(9) by _Donovan Johnson_, Sep 11 2009