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A122250 Partial sums of A004128. 2
0, 1, 3, 7, 12, 18, 26, 35, 45, 58, 72, 87, 104, 122, 141, 162, 184, 207, 233, 260, 288, 318, 349, 381, 415, 450, 486, 526, 567, 609, 653, 698, 744, 792, 841, 891, 944, 998, 1053, 1110, 1168 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..1000

FORMULA

G.f.: (1/(1-x))*Sum{k=0..infinity} ( x^(3^k)/((1-x)*(1-x^(3^k))) ).

a(n) = Sum_{j=0..n} ( Sum_{k=0..j} floor(j/3^k) ).

MATHEMATICA

Table[Sum[Sum[Floor[3*j/3^k], {k, 1, j}], {j, 0, n}], {n, 0, 50}] (* G. C. Greubel, May 14 2017 *)

PROG

(PARI) for(n=0, 50, print1(sum(j=0, n, sum(k=0, j, floor(j/3^k))), ", ")) \\ G. C. Greubel, May 14 2017

CROSSREFS

Sequence in context: A005228 A000969 A194117 * A169679 A024388 A184534

Adjacent sequences:  A122247 A122248 A122249 * A122251 A122252 A122253

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Aug 27 2006

STATUS

approved

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Last modified July 11 20:03 EDT 2020. Contains 335652 sequences. (Running on oeis4.)