A390877 - OEIS

A390877

Triangle read by rows: T(n,k) = A237271(k)*A000041(n-k), 1 <= k <= n.

1, 1, 1, 2, 1, 2, 3, 2, 2, 1, 5, 3, 4, 1, 2, 7, 5, 6, 2, 2, 1, 11, 7, 10, 3, 4, 1, 2, 15, 11, 14, 5, 6, 2, 2, 1, 22, 15, 22, 7, 10, 3, 4, 1, 3, 30, 22, 30, 11, 14, 5, 6, 2, 3, 2, 42, 30, 44, 15, 22, 7, 10, 3, 6, 2, 2, 56, 42, 60, 22, 30, 11, 14, 5, 9, 4, 2, 1, 77, 56, 84, 30, 44, 15, 22, 7, 15, 6, 4, 1, 2

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OFFSET

1,4

LINKS

Table of n, a(n) for n=1..91.

EXAMPLE

Triangle begins:

1, 1;

2, 1, 2;

3, 2, 2, 1;

5, 3, 4, 1, 2;

7, 5, 6, 2, 2, 1;

11, 7, 10, 3, 4, 1, 2;

15, 11, 14, 5, 6, 2, 2, 1;

22, 15, 22, 7, 10, 3, 4, 1, 3;

30, 22, 30, 11, 14, 5, 6, 2, 3, 2;

42, 30, 44, 15, 22, 7, 10, 3, 6, 2, 2;

56, 42, 60, 22, 30, 11, 14, 5, 9, 4, 2, 1;

77, 56, 84, 30, 44, 15, 22, 7, 15, 6, 4, 1, 2;

...

CROSSREFS

Columns starting with 1 give A000041.

Columns starting with 2 give A139582.

Columns starting with 3 give A299473.

Columns starting with 4 give A299474.

Leading diagonal gives A237271.

Row sums give A390878.

Cf. A221529, A384931, A390879.

Sequence in context: A182598 A331084 A067694 * A131810 A365143 A233519

Adjacent sequences: A390874 A390875 A390876 * A390878 A390879 A390880

KEYWORD

nonn,tabl

AUTHOR

Omar E. Pol, Nov 27 2025

STATUS

approved