A357451 Number of compositions (ordered partitions) of n into tribonacci numbers 1,2,4,7,13,24, ... (A000073).

1, 1, 2, 3, 6, 10, 18, 32, 57, 101, 179, 318, 564, 1002, 1778, 3157, 5603, 9947, 17656, 31342, 55635, 98759, 175308, 311191, 552400, 980571, 1740625, 3089803, 5484750, 9736045, 17282576, 30678512, 54457808, 96668726, 171597851, 304605465, 540708924

Offset: 0

Author

Ilya Gutkovskiy, Sep 29 2022

Keywords

• nonn

Crossrefs

Cf. A000073, A076739, A117546, A240844, A357453, A357455.

Programs

Mathematica

A000073[0] = A000073[1] = 0; A000073[2] = 1; A000073[n_] := A000073[n] = A000073[n - 1] + A000073[n - 2] + A000073[n - 3]; nmax = 36; CoefficientList[Series[1/(1 - Sum[x^A000073[k], {k, 3, 20}]), {x, 0, nmax}], x]

Formula

G.f.: 1 / (1 - Sum_{k>=3} x^A000073(k)).