A353128 Antidiagonal sums of A353109.

0, 0, 1, 4, 10, 20, 35, 20, 39, 48, 57, 40, 61, 58, 68, 92, 59, 96, 105, 114, 79, 118, 106, 116, 149, 98, 153, 162, 171, 118, 175, 154, 164, 206, 137, 210, 219, 228, 157, 232, 202, 212, 263, 176, 267, 276, 285, 196, 289, 250, 260, 320, 215, 324, 333, 342, 235, 346

Offset: 0

Author

Stefano Spezia, Apr 24 2022

Keywords

• nonn
• base
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,-1).

Crossrefs

Cf. A004247, A010888, A353109, A353933.

Programs

Mathematica

LinearRecurrence[{0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,-1},{0,0,1,4,10,20,35,20,39,48,57,40,61,58,68,92,59,96,105},58]

Formula

G.f.: x^2*(1 + 4*x + 10*x^2 + 20*x^3 + 35*x^4 + 20*x^5 + 39*x^6 + 48*x^7 + 55*x^9 + 32*x^10 + 41*x^11 + 18*x^12 - 2*x^13 - 19*x^15 + 105*x^17 + x^18 + 3*x^19 + 6*x^20 + 10*x^21 + 15*x^22 + 89*x^23 + 19*x^24 + 9*x^25 - 48*x^26)/((1 - x)^2*(1 + x + x^2)^2*(1 + x^3 + x^6)^2).

a(n) = 2*a(n-9) - a(n-18) for n > 18.