A329114 a(n) = floor(A026532(n)/5).

0, 0, 1, 3, 7, 21, 43, 129, 259, 777, 1555, 4665, 9331, 27993, 55987, 167961, 335923, 1007769, 2015539, 6046617, 12093235, 36279705, 72559411, 217678233, 435356467, 1306069401, 2612138803, 7836416409, 15672832819, 47018498457, 94036996915, 282110990745

Offset

1,4

Links

Table of n, a(n) for n=1..32.

Index entries for linear recurrences with constant coefficients, signature (0,7,0,-6).

Formula

a(n+1) = 3*a(n) if n is odd, a(n+1) = 2*a(n)+1 if n is even.

a(n) = f(3^f(n/2) * 2^f((n-1)/2) / 5), where f = floor.

G.f.: (x^2 (1 + 3 x))/((-1 + x) (1 + x) (-1 + 6 x^2)).

a(n) = 7*a(n-2) - 6*a(n-4).

Mathematica

s[1] = 1; s[n_] := If[IntegerQ[n/2], 3*s[n - 1], 2*s[n - 1]]
Table[s[n], {n, 1, 20}] (* A026549 *)
Table[Floor[s[n]/5], {n, 1, 50}] (* A329114 *)

Crossrefs

Cf. A026532, A329115.

Sequence in context: A128402 A018689 A119959 * A018712 A183936 A027151

Adjacent sequences: A329111 A329112 A329113 * A329115 A329116 A329117

Keyword

nonn,easy

Author

Clark Kimberling, Nov 10 2019

Status

approved