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A239367 The bisection of A238315 that remains constant with changes in the offset of the exponent of the second term. 1
1, 5, 13, 29, 69, 197, 669, 2509, 9813, 38965, 155501, 621565, 2485733, 9942309, 39768509, 159073197, 636291829, 2545166229, 10180663693, 40722653405, 162890612101, 651562446725, 2606249785053, 10424999138189 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Last digits repeat {1,5,3,9,9,7,9,9,3,5}

LINKS

Table of n, a(n) for n=1..24.

FORMULA

Conjectures from Colin Barker, Dec 30 2014: (Start)

a(n) = (-1+4^n-12*n+36*n^2)/27.

a(n) = 6*a(n-1)-8*a(n-2)-2*a(n-3)+9*a(n-4)-4*a(n-5).

G.f.: -x*(7*x^2+2*x-1) / ((x-1)^3*(4*x-1)).

(End)

CROSSREFS

Cf. A238315.

Sequence in context: A099970 A073857 A295112 * A124698 A147278 A268963

Adjacent sequences:  A239364 A239365 A239366 * A239368 A239369 A239370

KEYWORD

nonn

AUTHOR

Richard R. Forberg, Mar 30 2014

STATUS

approved

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Last modified October 22 04:25 EDT 2019. Contains 328315 sequences. (Running on oeis4.)