1,3

Let A, B, C are integers. We have a class of sequences a(n)= d(A*a(n-1)+B) if a(n-1) is not divisible by C, else a(n)= a(n-1)/C.

a(n)= d(n*a(n-1)) if a(n-1)is not divisible by 2 else a(n)= a(n-1)/2 . d(n*a(n-1)) is the number of divisors of n*a(n-1)

Cf. A000005.

Sequence in context: A049400 A106382 A004741 this_sequence A145034 A125158 A112384

Adjacent sequences: A133920 A133921 A133922 this_sequence A133924 A133925 A133926

nonn,uned

Ctibor O. ZIZKA (ctibor.zizka(AT)seznam.cz), Jan 07 2008