A167632 Smallest m such that A033183(m) = n.

0, 4, 36, 72, 108, 144, 180, 216, 252, 288, 324, 360, 396, 432, 468, 504, 540, 576, 612, 648, 684, 720, 756, 792, 828, 864, 900, 936, 972, 1008, 1044, 1080, 1116, 1152, 1188, 1224, 1260, 1296, 1332, 1368, 1404, 1440, 1476, 1512, 1548, 1584, 1620, 1656, 1692

Offset

0,2

Comments

A033183(a(n)) = n and A033183(m) < n for m < a(n);

for n>1: a(n) = A044102(n-1).

Links

Paolo Xausa, Table of n, a(n) for n = 0..10000

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

Formula

From Chai Wah Wu, Jun 16 2026: (Start)

a(n) = 2*a(n-1) - a(n-2) for n > 3.

G.f.: 4*x*(x^2 + 7*x + 1)/(x - 1)^2. (End)

E.g.f.: 4*(9 + 9*exp(x)*(x - 1) + x). - Stefano Spezia, Jun 18 2026

Mathematica

LinearRecurrence[{2, -1}, {0, 4, 36, 72}, 50] (* Paolo Xausa, Jun 18 2026 *)

Crossrefs

Cf. A033183, A044102.

Sequence in context: A173618 A091722 A053939 * A072157 A075215 A193833

Adjacent sequences: A167629 A167630 A167631 * A167633 A167634 A167635

Keyword

nonn,easy

Author

Reinhard Zumkeller, Nov 07 2009

Status

approved