A395463 a(n) = n*(7^n - 1) + 1.

1, 7, 97, 1027, 9601, 84031, 705889, 5764795, 46118401, 363182455, 2824752481, 21750594163, 166095446401, 1259557135279, 9495123019873, 71213422649131, 531726889113601, 3954718737782503, 29311444762388065, 216579008522089699, 1595845325952240001, 11729463145748964127

Offset

0,2

Comments

A sequence that occurs in A394332.

Links

James C. McMahon, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (16,-78,112,-49).

Formula

a(n) = A050919(n) + n + 1 = A036293(n) - n + 1.

G.f.: ( 1-9*x+63*x^2-91*x^3 ) / ( (7*x-1)^2*(x-1)^2 ). - R. J. Mathar, May 11 2026

Mathematica

a[n_]:=n*(7^n - 1) + 1; Array[a, 22, 0] (* or *)
LinearRecurrence[{16, -78, 112, -49}, {1, 7, 97, 1027}, 22] (* James C. McMahon, Apr 30 2026 *)

Crossrefs

Cf. A036293, A050919, A394332.

Sequence in context: A173833 A093172 A074110 * A155644 A243867 A232290

Adjacent sequences: A395460 A395461 A395462 * A395464 A395465 A395466

Keyword

nonn,easy

Author

A.H.M. Smeets, Apr 23 2026

Status

approved