A348707 Number of tree polyominoes with width 4 and height n.

1, 22, 243, 2024, 14981, 104946, 716045, 4816620, 32149313, 213645182, 1416316877, 9376424198, 62027820325, 410158517056, 2711528337463, 17923333338880, 118465285682767, 782970312006472, 5174749541752549, 34200123937114224, 226028308969773551, 1493812891834066696

Offset

1,2

Links

Table of n, a(n) for n=1..22.

Maxime Samson, Valence de graphes et polyominos arbres, Mémoire, Trois-Rivières, Université du Québec à Trois-Rivières, 152 p., 2020.

Index entries for linear recurrences with constant coefficients, signature (15, -74, 86, 523, -2461, 4161, 681, -17782, 40652, -50933, 23841, 65154, -202154, 306084, -279336, 135024, -16128, -9216, 2304).

Formula

G.f.: (x + 7*x^2 - 13*x^3 - 79*x^4 + 188*x^5 + 64*x^6 - 723*x^7 + 831*x^8 - 335*x^9 + 185*x^10 + 2890*x^11 - 5272*x^12 - 192*x^13+4008*x^14 - 9368*x^15 + 10728*x^16 + 1680*x^17 - 1824*x^18 - 576*x^19)/((1 - 2*x)*(1 - 5*x + 4*x^2 + 7*x^3 - 21*x^4 + 24*x^5 - 6*x^6)*(1 - 8*x + 4*x^2 + 55*x^3 - 167*x^4 + 180*x^5 + 214*x^6 - 653*x^7 + 1232*x^8 - 2428*x^9 + 1968*x^10 - 96*x^11 - 192*x^12)).

Crossrefs

Cf. A348663.

Sequence in context: A249086 A300624 A249087 * A249088 A249089 A249090

Adjacent sequences: A348704 A348705 A348706 * A348708 A348709 A348710

Keyword

nonn,easy

Author

Maxime Samson, Oct 30 2021

Status

approved