A086733 - OEIS

%I #9 Jul 18 2021 14:20:39

%S 1,4,9,19,31,54,74,117,148,217,252,366,408,562,612,833,853,1171,1203,

%T 1566,1606,2104,2030,2718,2655,3347,3332,4262,3954,5226,4984,6161,

%U 5971,7566,6874,8961,8361,10194,9732,12210,10912,14122,13012,15654,14858,18494

%N Convolution of sigma(n) with phi(n).

%C Convolution of A340793 and the nonzero terms of A002088. - _Omar E. Pol_, Feb 17 2021

%t Table[ListConvolve[DivisorSigma[1,Range[n]],EulerPhi[Range[n]]],{n,50}]// Flatten (* _Harvey P. Dale_, Jul 18 2021 *)

%Y Cf. A000010, A000203, A002088, A340793.

%K nonn

%O 1,2

%A _Jon Perry_, Jul 29 2003