A081249 Partial sums of A081134.

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

Author

Klaus Brockhaus, Mar 17 2003

Keywords

• easy
• nonn

Examples

			First seven terms of A081134 are 0,1,0,1,2,3,2, so a(7) = 9.
		

Links

• Klaus Brockhaus, Illustration for A081134, A081249, A081250 and A081251

Programs

Mathematica

Accumulate[Flatten[Table[Join[Range[0,3^n],Range[3^n-1,1,-1]],{n,0,4}]]] (* Harvey P. Dale, Sep 21 2016 *)

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),","))}

Formula

a(n) = sum{j=1..n, A081134(j)}.