A169604 a(n) = 3*6^n.

3, 18, 108, 648, 3888, 23328, 139968, 839808, 5038848, 30233088, 181398528, 1088391168, 6530347008, 39182082048, 235092492288, 1410554953728, 8463329722368, 50779978334208, 304679870005248, 1828079220031488, 10968475320188928, 65810851921133568, 394865111526801408

Offset

0,1

Comments

Essentially first differences of A125682.

Binomial transform of A005053 without initial term 1.

Second binomial transform of A164346.

Inverse binomial transform of A169634.

Second inverse binomial transform of A103333 without initial term 1.

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..300

Index entries for linear recurrences with constant coefficients, signature (6).

Formula

a(n) = 6*a(n-1) for n > 0; a(0) = 3.

G.f.: 3/(1-6*x).

a(n) = A081341(n+1).

From Reinhard Zumkeller, May 02 2010: (Start)

a(n) = 3*A000400(n) = A000400(n+1)/2.

a(n) = A003586(A014105(n+1)). (End)

E.g.f.: 3*exp(6*x). - Elmo R. Oliveira, Oct 14 2025

Mathematica

3*6^Range[0, 25] (* Paolo Xausa, Jan 17 2025 *)

Prog

(Magma) [ 3*6^n: n in [0..19] ];
(PARI) a(n)=3*6^n \\ Charles R Greathouse IV, Oct 16 2015

Crossrefs

Cf. A081341, A125682 ((6^n-1)*3/5), A005053 (expand (1-2*x)/(1-5*x)), A164346 (3*4^n), A169634 (3*7^n), A103333 (expand (1-5*x)/(1-8*x)).

Cf. A000400, A014105.

Subsequence of A003586

Sequence in context: A137962 A267662 A081341 * A355353 A363439 A132900

Adjacent sequences: A169601 A169602 A169603 * A169605 A169606 A169607

Keyword

nonn,easy

Author

Klaus Brockhaus, Apr 04 2010

Status

approved