login
A129644
The concatenated list of the positive divisors of the terms of sequence A129643. Also, a(n) = A129643(n+1)/A129643(n) -1.
2
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
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 A374577 A104778
KEYWORD
nonn,base
AUTHOR
Leroy Quet, Apr 25 2007
EXTENSIONS
More terms from R. J. Mathar, Oct 16 2007
STATUS
approved