A264767 a(1)=1; for n>1, a(n) = a(n-1) + n if x=0, otherwise a(n) = a(n-1) / 2^x, where x is the exponent of highest power of 2 dividing gcd(a(n-1),n).

1, 3, 6, 3, 8, 4, 11, 19, 28, 14, 25, 37, 50, 25, 40, 5, 22, 11, 30, 15, 36, 18, 41, 65, 90, 45, 72, 18, 47, 77, 108, 27, 60, 30, 65, 101, 138, 69, 108, 27, 68, 34, 77, 121, 166, 83, 130, 65, 114, 57, 108, 27, 80, 40, 95, 151, 208, 104, 163, 223, 284, 142, 205, 269, 334, 167, 234, 117, 186, 93, 164, 41, 114, 57, 132, 33, 110, 55, 134, 67, 148, 74, 157, 241, 326, 163, 250, 125, 214, 107, 198, 99, 192, 96, 191, 287, 384, 192, 291, 391, 492, 246

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

nxt[{n_, a_}]:=Module[{x=IntegerExponent[GCD[a, n+1], 2]}, {n+1, If[x== 0, a+n+1, a/2^x]}]; NestList[nxt, {1, 1}, 110][[All, 2]]

Crossrefs

Cf. A007814, A133058.

Sequence in context: A090895 A337903 A358787 * A065231 A351102 A019918

Adjacent sequences: A264764 A264765 A264766 * A264768 A264769 A264770

Keyword

nonn

Author

Ctibor O. Zizka, Nov 23 2015

Status

approved