A133389 Start with a(1)=1; now a(n+1)=a(n)+a(k) with k=[n-n-th digit of Pi]. If k<0 or k=0, then a(k)=0.

1, 1, 2, 2, 4, 4, 4, 8, 9, 11, 15, 19, 21, 23, 27, 31, 52, 79, 106, 121, 152, 179, 300, 352, 473, 652, 952, 1058, 1531, 2483, 2783, 2962, 3914, 7828, 10790, 11742, 12800, 16714, 29514, 31997, 35911, 67908, 79650, 87478, 123389, 135131, 147931, 235409, 271320

Offset

1,3

Comments

Terms of this "Pibonacci sequence" computed by Gilles Sadowski.

Links

Gilles Sadowski, Table of n, a(n) for n = 1..101

Example

For n=7 we have a(8)=a(7)+a(k) with k=(7-2) [because "2" is the 7th digit of Pi: 3,1,4,1,5,9,(2),6...] So a(8)=a(7)+a(5)=4+4=8.

Crossrefs

Sequence in context: A033720 A033728 A033744 * A320196 A033740 A303800

Adjacent sequences: A133386 A133387 A133388 * A133390 A133391 A133392

Keyword

base,easy,nonn

Author

Eric Angelini, Nov 23 2007

Status

approved