A129644 The concatenated list of the positive divisors of the terms of sequence A129643. Also, a(n) = A129643(n+1)/A129643(n) -1.

1, 1, 2, 1, 2, 4, 1, 2, 3, 4, 6, 12, 1, 2, 3, 4, 6, 8, 12, 24, 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72, 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 30, 36, 40, 45, 60, 72, 90, 120, 180, 360, 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120

Offset

1,3

Links

Table of n, a(n) for n=1..81.

Maple

A129644 := proc(nmax) local a, b, n, a_1; a := [1] ; b := [1] ; while nops(b) < nmax do n := nops(a)+1 ; a_1 := op(-1, a) ; a := [op(a), a_1*(op(n-1, b)+1)] ; a_1 := op(-1, a) ; b := [op(b), op(numtheory[divisors](a_1))] ; od: RETURN(b) ; end: A129644(80) ; # R. J. Mathar, Oct 16 2007

Crossrefs

Cf. A129643.

Sequence in context: A198069 A300792 A132082 * A081517 A104778 A356184

Adjacent sequences: A129641 A129642 A129643 * A129645 A129646 A129647

Keyword

nonn,base

Author

Leroy Quet, Apr 25 2007

Extensions

More terms from R. J. Mathar, Oct 16 2007

Status

approved