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A081249
Partial sums of A081134.
5
0, 1, 1, 2, 4, 7, 9, 10, 10, 11, 13, 16, 20, 25, 31, 38, 46, 55, 63, 70, 76, 81, 85, 88, 90, 91, 91, 92, 94, 97, 101, 106, 112, 119, 127, 136, 146, 157, 169, 182, 196, 211, 227, 244, 262, 281, 301, 322, 344, 367, 391, 416, 442, 469, 495, 520, 544, 567, 589, 610, 630
OFFSET
1,4
FORMULA
a(n) = sum{j=1..n, A081134(j)}.
EXAMPLE
First seven terms of A081134 are 0,1,0,1,2,3,2, so a(7) = 9.
MATHEMATICA
Accumulate[Flatten[Table[Join[Range[0, 3^n], Range[3^n-1, 1, -1]], {n, 0, 4}]]] (* Harvey P. Dale, Sep 21 2016 *)
PROG
(PARI) {s=0; for(n=1, 62, p=3^floor(0.1^25+log(n)/log(3)); print1(s=s+min(n-p, 3*p-n), ", "))}
CROSSREFS
Sequence in context: A366114 A199465 A288305 * A327217 A327207 A279934
KEYWORD
easy,nonn
AUTHOR
Klaus Brockhaus, Mar 17 2003
STATUS
approved