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A013777
a(n) = 2^(4*n + 3).
8
8, 128, 2048, 32768, 524288, 8388608, 134217728, 2147483648, 34359738368, 549755813888, 8796093022208, 140737488355328, 2251799813685248, 36028797018963968, 576460752303423488, 9223372036854775808, 147573952589676412928, 2361183241434822606848, 37778931862957161709568
OFFSET
0,1
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)
MATHEMATICA
2^(4*Range[0, 20] + 3) (* or *)
NestList[16*# &, 8, 20] (* Paolo Xausa, Jul 21 2025 *)
NestList[16#&, 8, 20] (* Harvey P. Dale, Jan 29 2026 *)
PROG
(SageMath) [lucas_number1(4*n, 2, 0) for n in range(1, 17)] # Zerinvary Lajos, Oct 27 2009
(Magma) [2^(4*n+3): n in [0..20]]; // Vincenzo Librandi, Jun 27 2011
(PARI) a(n)=8<<(4*n) \\ Charles R Greathouse IV, Apr 08 2012
CROSSREFS
Subsequence of A000079.
Cf. A004767.
Sequence in context: A301403 A317513 A300178 * A183497 A370102 A237023
KEYWORD
nonn,easy
STATUS
approved