A067440 - OEIS

%I #8 Dec 05 2013 19:55:08

%S 1,3,6,8,13,19,26,28,31,41,52,64,77,91,106,108,125,143,162,182,203,

%T 225,248,272,277,303,306,334,363,393,424,426,459,493,528,534,571,609,

%U 648,688,729,771,814,858,903,949,996,1044,1051,1101,1152,1204,1257,1311

%N Sum(i(n)), where i(n) is the smallest integer with i(n)^m=n for some m.

%e a(8) = 28, as the smallest integer roots of numbers from 1 to 8 respectively are 1,2,3,2,5,6,7 and 2. Their sum = 28.

%p q[1] := 1:for n from 2 to 100 do a := ifactors(n):c := a[2][1][2]; for i from 2 to nops(a[2]) do c := igcd(c,a[2][i][2]); end do:q[n] := simplify(n^(1/c)); end do:for n from 1 to 100 do w[n] := sum('q[i3]',i3=1..n): end do:ww := seq(w[j4],j4=1..100);

%K nonn

%O 1,2

%A _Amarnath Murthy_, Jan 29 2002

%E More terms from _Sascha Kurz_, Mar 18 2002