A365540 Antidiagonal sums of A365539.

0, 1, 5, 12, 24, 39, 61, 86, 118, 155, 199, 246, 304, 365, 433, 508, 592, 679, 777, 878, 990, 1109, 1235, 1364, 1508, 1657, 1813, 1976, 2150, 2327, 2519, 2714, 2920, 3133, 3353, 3580, 3824, 4071, 4325, 4586, 4862, 5141, 5435, 5732, 6040, 6359, 6685, 7014, 7362

Offset

0,3

Links

Table of n, a(n) for n=0..48.

Formula

a(n) = Sum_{m=1..n} (Sum_{k=1..m} (2*A000005(k) - 1)).

Mathematica

A365539[n_, k_]:=SeriesCoefficient[(1+x^k)/((1-x)^2*(1-x^k)), {x, 0, n}]; Table[Sum[A365539[n-k, k], {k, n}], {n, 0, 48}] (* or *)
Table[Sum[Sum[2  DivisorSigma[0, k]-1, {k, m}], {m, n}], {n, 0, 48}]

Crossrefs

Cf. A000005, A114003 (2nd differences), A365539.

Sequence in context: A018806 A101425 A191831 * A188182 A187210 A299901

Adjacent sequences: A365537 A365538 A365539 * A365541 A365542 A365543

Keyword

nonn

Author

Stefano Spezia, Sep 08 2023

Status

approved