A013777 a(n) = 2^(4*n + 3).

8, 128, 2048, 32768, 524288, 8388608, 134217728, 2147483648, 34359738368, 549755813888, 8796093022208, 140737488355328, 2251799813685248, 36028797018963968, 576460752303423488, 9223372036854775808, 147573952589676412928, 2361183241434822606848, 37778931862957161709568

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..200
• Tanya Khovanova, Recursive Sequences.
• Index to divisibility sequences.
• Index entries for linear recurrences with constant coefficients, signature (16).

Crossrefs

Subsequence of A000079.

Cf. A004767.

Programs

Magma

[2^(4*n+3): n in [0..20]]; // Vincenzo Librandi, Jun 27 2011

Mathematica

2^(4*Range[0, 20] + 3) (* or *)
NestList[16*# &, 8, 20] (* Paolo Xausa, Jul 21 2025 *)

PARI

a(n)=8<<(4*n) \\ Charles R Greathouse IV, Apr 08 2012

Sage

[lucas_number1(4*n, 2, 0) for n in range(1, 17)] # Zerinvary Lajos, Oct 27 2009

Formula

From Philippe Deléham, Nov 23 2008: (Start)

a(n) = 16*a(n-1); a(0)=8.

G.f.: 8/(1-16*x). (End)

From Elmo R. Oliveira, Feb 18 2025: (Start)

E.g.f.: 8*exp(16*x).

a(n) = A000079(A004767(n)). (End)