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A355859
Triangle read by rows: T(n,k) = (n + k)/2 if (n + k) is congruent to 0 (mod 2), otherwise T(n,k) = 0; n >= 1, k >= 1.
0
1, 0, 2, 2, 0, 3, 0, 3, 0, 4, 3, 0, 4, 0, 5, 0, 4, 0, 5, 0, 6, 4, 0, 5, 0, 6, 0, 7, 0, 5, 0, 6, 0, 7, 0, 8, 5, 0, 6, 0, 7, 0, 8, 0, 9, 0, 6, 0, 7, 0, 8, 0, 9, 0, 10, 6, 0, 7, 0, 8, 0, 9, 0, 10, 0, 11, 0, 7, 0, 8, 0, 9, 0, 10, 0, 11, 0, 12, 7, 0, 8, 0, 9, 0, 10, 0, 11, 0, 12, 0, 13, 0
OFFSET
1,3
COMMENTS
Row sums see A001318.
EXAMPLE
The triangle begins:
k=1 2 3 4 5 6
n=1: 1;
n=2: 0, 2;
n=3: 2, 0, 3;
n=4: 0, 3, 0, 4;
n=5: 3, 0, 4, 0, 5;
n=6: 0, 4, 0, 5, 0, 6;
and so on.
MATHEMATICA
T[n_, k_] := If[EvenQ[n + k], (n + k)/2, 0]; Table[T[n, k], {n, 1, 13}, {k, 1, n}] // Flatten (* Amiram Eldar, Jul 19 2022 *)
CROSSREFS
Cf. A001318, A138099 (without the zeros).
Sequence in context: A087319 A101348 A141659 * A294519 A123515 A058648
KEYWORD
nonn,tabl
AUTHOR
Ctibor O. Zizka, Jul 19 2022
STATUS
approved