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A362072
Antidiagonal sums of A336225.
3
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
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
KEYWORD
nonn,base,look
AUTHOR
Stefano Spezia, Apr 08 2023
STATUS
approved