A353593 Triangle read by rows. The Riordan square of the tetranacci numbers (A000078).

1, 1, 1, 2, 3, 1, 4, 8, 5, 1, 8, 20, 18, 7, 1, 15, 47, 56, 32, 9, 1, 29, 107, 158, 120, 50, 11, 1, 56, 238, 419, 397, 220, 72, 13, 1, 108, 520, 1063, 1207, 836, 364, 98, 15, 1, 208, 1120, 2608, 3452, 2871, 1563, 560, 128, 17, 1, 401, 2386, 6233, 9424, 9153, 5987, 2682, 816, 162, 19, 1

Offset

0,4

Comments

See A321620 for the definition of the Riordan square.

Links

Table of n, a(n) for n=0..65.

Example

Triangle starts:
[0]   1;
[1]   1,    1;
[2]   2,    3,    1;
[3]   4,    8,    5,    1;
[4]   8,   20,   18,    7,    1;
[5]  15,   47,   56,   32,    9,    1;
[6]  29,  107,  158,  120,   50,   11,   1;
[7]  56,  238,  419,  397,  220,   72,  13,   1;
[8] 108,  520, 1063, 1207,  836,  364,  98,  15,  1;
[9] 208, 1120, 2608, 3452, 2871, 1563, 560, 128, 17, 1.

Maple

# The function RiordanSquare is defined in A321620.
RiordanSquare(1/(1 - x - x^2 - x^3 - x^4), 10);

Crossrefs

Cf. A000078 (tetranacci), A160175 (row sums), A321620 (Riordan square).

Sequence in context: A021436 A377307 A187889 * A118800 A200139 A321621

Adjacent sequences: A353590 A353591 A353592 * A353594 A353595 A353596

Keyword

nonn,tabl

Author

Peter Luschny, Apr 29 2022

Status

approved