A264767 - OEIS

%I #12 Jul 18 2021 18:40:34

%S 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,

%T 45,72,18,47,77,108,27,60,30,65,101,138,69,108,27,68,34,77,121,166,83,

%U 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

%N 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).

%H Harvey P. Dale, <a href="/A264767/b264767.txt">Table of n, a(n) for n = 1..1000</a>

%t 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]]

%Y Cf. A007814, A133058.

%K nonn

%O 1,2

%A _Ctibor O. Zizka_, Nov 23 2015