A362072 Antidiagonal sums of A336225.

0, 0, 1, 4, 10, 20, 35, 20, 39, 48, 57, 58, 61, 58, 95, 110, 140, 114, 159, 186, 205, 172, 160, 134, 203, 206, 252, 216, 288, 262, 265, 280, 281, 260, 371, 354, 381, 282, 382, 430, 454, 410, 425, 392, 528, 510, 528, 466, 568, 628, 593, 626, 629, 594, 666, 684, 775

Offset

0,4

Links

Stefano Spezia, Table of n, a(n) for n = 0..10000

Formula

a(n) = Sum_{k=1..n} A007953(k*(n-k)). - Andrew Howroyd, Apr 08 2023

Mathematica

T[i_, j_]:=Total[IntegerDigits[i*j]]; Table[Sum[T[n-j, j], {j, 0, n}], {n, 0, 56}]

Prog

(PARI) a(n) = sum(k=1, n, sumdigits(k*(n-k))) \\ Andrew Howroyd, Apr 08 2023

Crossrefs

Cf. A003991, A007953, A336225, A353128.

Sequence in context: A008116 A301162 A353128 * A102533 A341133 A008033

Adjacent sequences: A362069 A362070 A362071 * A362073 A362074 A362075

Keyword

nonn,base,look

Author

Stefano Spezia, Apr 08 2023

Status

approved