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A309299 (1/7) times the sum of the elements of all subsets of [n] whose sum is divisible by seven. 2
0, 0, 0, 0, 2, 5, 15, 40, 97, 237, 571, 1385, 3263, 7618, 17580, 40146, 90962, 204618, 457446, 1016494, 2247000, 4943400, 10828248, 23625120, 51358776, 111277576, 240359368, 517697136, 1112090144, 2383049792, 5094795600, 10868896688, 23140232368, 49172993152 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,5
LINKS
Index entries for linear recurrences with constant coefficients, signature (6,-12,8,0,0,0,6,-36,72,-48,0,0,0,-12,72,-144,96,0,0,0,8,-48,96,-64).
FORMULA
G.f.: -x^4*(8*x^18+24*x^14-12*x^12+4*x^11+16*x^10-38*x^9+49*x^8 -15*x^7 +7*x^6 -15*x^5 +3*x^4 +6*x^3 -9*x^2+7*x-2) / ((2*x-1)^3 *(2*x^7-1)^3).
CROSSREFS
Column k=7 of A309280.
Sequence in context: A148345 A148346 A148347 * A151260 A148348 A148349
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Jul 21 2019
STATUS
approved

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Last modified February 26 12:54 EST 2024. Contains 370352 sequences. (Running on oeis4.)