A073723 Mod[Sigma[n],Pi[n]]=1 or Sigma[n]=kPi[n]+1.

4, 9, 16, 64, 69, 218, 592, 808, 910, 1921, 1957, 2648, 2860, 7609, 13462, 14953, 16838, 20688, 27050, 44471, 80440, 91860, 122351, 131095, 154606, 166121, 171396, 226831, 257467, 318016, 614626, 726560

Offset

1,1

Links

Table of n, a(n) for n=1..32.

Formula

A000203(n)=1+k.A000720(n)

Mathematica

Do[s=Mod[DivisorSigma[1, n], PrimePi[n]]; If[s==1, Print[n]], {n, 1, 1000000}]

Crossrefs

Cf. A000203, A000720, A072548, A073724.

Sequence in context: A023110 A277699 A368891 * A161493 A030075 A296111

Adjacent sequences: A073720 A073721 A073722 * A073724 A073725 A073726

Keyword

nonn

Author

Labos Elemer, Aug 05 2002

Status

approved