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A137798 Partial sums of A137797. 1
0, 0, 4, 8, 16, 14, 16, 18, 24, 30, 30, 30, 34, 38, 46, 44, 46, 48, 54, 60, 60, 60, 64, 68, 76, 74, 76, 78, 84, 90, 90, 90, 94, 98, 106, 104, 106, 108, 114, 120, 120, 120, 124, 128, 136, 134, 136, 138, 144, 150, 150, 150, 154, 158, 166, 164, 166, 168, 174, 180, 180, 180 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..61.

Index entries for linear recurrences with constant coefficients, signature (0,1,0,0,1,0,-1).

FORMULA

f(n) = Sum{k=0,n} 2*((k+1) mod 5) - 2*((k+1) mod 2).

a(n) = a(n-2)+a(n-5)-a(n-7) for n>6. - Colin Barker, Dec 16 2014

G.f.: 2*x^2*(3*x^3+6*x^2+4*x+2) / ((x-1)^2*(x+1)*(x^4+x^3+x^2+x+1)). - Colin Barker, Dec 16 2014

MATHEMATICA

Accumulate[LinearRecurrence[{-1, 0, 0, 0, 1, 1}, {0, 0, 4, 4, 8, -2, 2}, 100]] (* or *) LinearRecurrence[{0, 1, 0, 0, 1, 0, -1}, {0, 0, 4, 8, 16, 14, 16}, 100] (* Harvey P. Dale, Jun 08 2015 *)

PROG

Python (Complete):

.Sequence = []

.l = range('Choose Range')

.while len(l) > 0:

... a = l.pop(0)

... z = sum(2*((x+1)%5)-2*((x+1)%2) for x in range(a))

... Sequence.append(z)

.print Sequence

(PARI) concat([0, 0], Vec(2*x^2*(3*x^3+6*x^2+4*x+2)/((x-1)^2*(x+1)*(x^4+x^3+x^2+x+1)) + O(x^100))) \\ Colin Barker, Dec 16 2014

CROSSREFS

Cf. A137797.

Sequence in context: A111988 A110652 A059373 * A312754 A312755 A312756

Adjacent sequences:  A137795 A137796 A137797 * A137799 A137800 A137801

KEYWORD

easy,nonn

AUTHOR

William A. Tedeschi, Feb 10 2008

STATUS

approved

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Last modified January 20 00:45 EST 2022. Contains 350467 sequences. (Running on oeis4.)