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A374426
a(n) = n*(n + 1)/2 + pi(n), where pi(n) = A000720(n) is the prime counting function.
1
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
OFFSET
1,2
LINKS
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}]
PROG
(PARI) a(n) = n*(n+1)/2 + primepi(n); \\ Michel Marcus, Jul 31 2024
CROSSREFS
Partial sums of A014683.
Sequence in context: A311635 A049621 A072511 * A156324 A311636 A311637
KEYWORD
nonn
AUTHOR
James C. McMahon, Jul 08 2024
STATUS
approved