A158185 Let b(n) the sequence of zero plus the natural numbers (0+A000027). At any step n=1,2,3,4,... add b(n-1) to the number in position n+b(n).

1, 2, 3, 5, 5, 8, 7, 8, 12, 15, 11, 12, 13, 27, 15, 23, 17, 18, 19, 20, 29, 37, 23, 35, 37, 38, 27, 28, 29, 57, 31, 32, 33, 57, 35, 53, 37, 56, 54, 59, 54, 42, 43, 44, 45, 83, 47, 48, 49, 70, 51, 52, 53, 92, 55, 83, 57, 86, 111, 60, 61, 154, 63, 132, 65, 98, 67, 68, 69, 127, 71

Offset

0,2

Links

Table of n, a(n) for n=0..70.

Example

Start from b(n)=0,1,2,3,4,5,6,7,8,9,10,...... [n(0)=0].
First step n=1: add b(n-1)=b(0)=0 to n+b(n)=2 (practically no change).
Second step n=2: add b(n-1)=b(1)=1 to n+b(n)=4 -> 0,1,2,3,5,5,6,7,8,9,...
Third step n=3: add b(n-1)=b(2)=2 to n+b(n)=6 -> 0,1,2,3,5,5,8,7,8,9,...
Fourth step n=4: add b(n-1)=b(3)=3 to n+b(n)=8 -> 0,1,2,3,5,5,8,7,8,12,...
Etc.

Maple

P:=proc(i) local n, v; v:=array(1..i); for n from 1 by 1 to i do v[n]:=n; od; for n from 2 by 1 to 200 do v[v[n]+n]:=v[v[n]+n]+v[n-1]; od; for n from 1 by 1 to 200 do print(v[n]); od; end: P(1000);

Crossrefs

A000027

Sequence in context: A053148 A295798 A072728 * A095413 A134871 A267453

Adjacent sequences: A158182 A158183 A158184 * A158186 A158187 A158188

Keyword

easy,nonn

Author

Paolo P. Lava & Giorgio Balzarotti, Mar 13 2009

Status

approved