A291105 Number of maximal irredundant sets in the n-web graph.

26, 58, 182, 540, 1290, 3690, 10160, 28786, 80841, 223888, 624613, 1743972, 4865441, 13595466, 37944869, 105893100, 295608956, 825144438, 2303387028, 6429909987, 17948364550, 50101571688, 139855118057, 390395847523, 1089765919988, 3042007560076, 8491555206270

Offset

3,1

Links

Christian Sievers, Table of n, a(n) for n = 3..200

Eric Weisstein's World of Mathematics, Maximal Irredundant Set.

Eric Weisstein's World of Mathematics, Web Graph.

Index entries for linear recurrences with constant coefficients, signature (2,1,4,-2,4,3,-26,-14,-48,65,23,-22,10,-76,54,2,21).

Formula

a(n) = 2*a(n-1)+a(n-2)+4*a(n-3)-2*a(n-4)+4*a(n-5)+3*a(n-6)-26*a(n-7)-14*a(n-8)-48*a(n-9)+65*a(n-10)+23*a(n-11)-22*a(n-12)+10*a(n-13)-76*a(n-14)+54*a(n-15)+2*a(n-16)+21*a(n-17). - Eric W. Weisstein, Sep 30 2025

Mathematica

LinearRecurrence[{2, 1, 4, -2, 4, 3, -26, -14, -48, 65, 23, -22, 10, -76, 54, 2, 21}, {26, 58, 182, 540, 1290, 3690, 10160, 28786, 80841, 223888, 624613, 1743972, 4865441, 13595466, 37944869, 105893100, 295608956}, 20] (* Eric W. Weisstein, Sep 30 2025 *)

Crossrefs

Sequence in context: A161341 A038861 A277976 * A267294 A385893 A162316

Adjacent sequences: A291102 A291103 A291104 * A291106 A291107 A291108

Keyword

nonn,easy

Author

Eric W. Weisstein, Aug 17 2017

Extensions

a(9) from Eric W. Weisstein, May 21 2019

a(10)-a(11) from Andrew Howroyd, Sep 08 2019

More terms from Christian Sievers, Nov 15 2023

Status

approved