A374426 Contribution to the OEIS

 This was my 20th sequence published by the OEIS and my 250th contribution.

A374426 a(n) = n*(n + 1)/2 + pi(n), where pi(n) = A000720(n) is the prime counting function. 0

1, 4, 8, 12, 18, 24, 32, 40, 49, 59, 71, 83, 97, 111, 126, 142, 160, 178, 198, 218, 239, 261, 285, 309, 334, 360, 387, 415, 445, 475, 507, 539, 572, 606, 641, 677, 715, 753, 792, 832, 874, 916, 960, 1004, 1049, 1095, 1143, 1191, 1240, 1290, 1341, 1393, 1447 (list; graph; refs; listen; history; edit; text; internal format)

OFFSET 1,2 LINKS James C. McMahon, Table of n, a(n) for n = 1..10000 FORMULA a(n) = A000217(n) + A000720(n). a(1) = 1; for n > 1: a(n) = a(n-1) + n + A010051(n). MATHEMATICA Table[n(n+1)/2+PrimePi[n], {n, 53}] CROSSREFS Cf. A000217, A000720, A010051, A256885. Partial sums of A014683. Sequence in context: A311635 A049621 A072511 * A156324 A311636 A311637 Adjacent sequences: A374423 A374424 A374425 * A374427 A374428 A374429 KEYWORD nonn,new AUTHOR James C. McMahon, Jul 08 2024 STATUS approved