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Integer averages of first n perfect powers for some n.
0

%I #13 Oct 05 2013 12:21:01

%S 1,198,1070,2574,10769,66908,1036663,6436241,12745650,2253183029,

%T 81422343214,278747505724,352663623088,537668537432,807810573770,

%U 3169762558125,3623176921864,4225712901909,4395991005975,15435175116616,1361811565229752

%N Integer averages of first n perfect powers for some n.

%e 198 is average of first n=33 perfect powers, 1070 (n=73), 2574 (n=111), 10769 (n=219), 66908 (n=519), 1036663 (n=1943).

%o (PARI) lista(nn) = {vec = vector(nn, i, i); pp = concat(1, select(i->ispower(i) , vec)); s = 0; for (i = 1, #pp, s += pp[i]; if ((s % i) == 0, print1(s/i, ", ")););} \\ _Michel Marcus_, Oct 02 2013

%Y Cf. A001597.

%K easy,nonn

%O 1,2

%A _Zak Seidov_, Oct 11 2002

%E Extended by _Robert G. Wilson v_, Oct 14 2002

%E a(8)-a(21) from _Donovan Johnson_, Oct 05 2013