A355860 - OEIS

A355860

Triangle read by rows: T(n,k) = n*k/(n + k) if n+k divides n*k, otherwise T(n,k) = 0; n >= 1, k >= 1.

0, 0, 1, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 4, 0, 0, 0, 0, 0, 6

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OFFSET

1,10

LINKS

Table of n, a(n) for n=1..78.

EXAMPLE

The triangle begins:

0, 1;

0, 0, 0;

0, 0, 0, 2;

0, 0, 0, 0, 0;

0, 0, 2, 0, 0, 3;

and so on.

MATHEMATICA

T[n_, k_] := If[Divisible[n*k, n + k], n*k/(n + k), 0]; Table[T[n, k], {n, 1, 12}, {k, 1, n}] // Flatten (* Amiram Eldar, Jul 20 2022 *)

CROSSREFS

Sequence in context: A112314 A350872 A280799 * A374089 A104261 A028702

Adjacent sequences: A355857 A355858 A355859 * A355861 A355862 A355863

KEYWORD

nonn,tabl

AUTHOR

Ctibor O. Zizka, Jul 19 2022

STATUS

approved