A130158 Table read by rows in which row n lists the positive divisors of A130157(n).

1, 1, 1, 2, 1, 3, 1, 3, 1, 5, 1, 2, 4, 1, 7, 1, 2, 3, 6, 1, 3, 9, 1, 3, 9, 1, 11, 1, 3, 9, 1, 2, 5, 10, 1, 2, 7, 14, 1, 13, 1, 2, 4, 8, 16, 1, 11, 1, 2, 3, 4, 6, 12, 1, 7, 1, 2, 4, 5, 10, 20, 1, 2, 7, 14, 1, 3, 5, 15, 1, 23, 1, 2, 4, 8, 16, 1, 17, 1, 2, 13, 26

Offset

1,4

Links

Table of n, a(n) for n=1..82.

Example

Triangle starts:
1;
1;
1, 2;
1, 3;
1, 3;
1, 5;
1, 2, 4;
1, 7;
1, 2, 3, 6;
...

Maple

A130158 := proc(nmax) local a130157, a, n, anext, i ; a130157 := [1] ; a := [] ; while nops(a) < nmax do n := nops(a130157)+1 ; a := [op(a), op(numtheory[divisors](op(-1, a130157)))] ; anext :=0 ; for i from 1 to nops(a130157) do if gcd(op(i, a130157), op(n-1, a)) = 1 then anext := anext+1 ; fi ; od ; a130157 := [op(a130157), anext] ; od ; RETURN(a) ; end: A130158(80) ; # R. J. Mathar, Jun 12 2007

Crossrefs

Cf. A130157.

Sequence in context: A029227 A029214 A134460 * A352930 A187497 A325704

Adjacent sequences: A130155 A130156 A130157 * A130159 A130160 A130161

Keyword

nonn,tabf

Author

Leroy Quet, May 13 2007

Extensions

More terms from R. J. Mathar, Jun 12 2007

Edited by Charles R Greathouse IV, Apr 30 2010

Edited by N. J. A. Sloane, May 09 2010

Status

approved