A073722 Least x such that Mod[Sigma[x],Pi[x]]=n or zero if no such number exists.

4, 10, 8, 17, 42, 23, 111, 32, 59, 31, 67, 49, 110, 63, 60, 82, 84, 89, 75, 191, 98, 141, 97, 101, 256, 171, 169, 148, 144, 140, 159, 143, 222, 220, 172, 206, 2124, 183, 315, 263, 567, 201, 358, 204, 470, 243, 391, 264, 563, 295, 382, 290, 285, 313, 324, 307

Offset

1,1

Links

Table of n, a(n) for n=1..56.

Formula

a(n)=Min{x; Mod[A000203(x)/A000720(x)]=n}

Example

n=8: a(8)=32 since Sigma[32]=63,Pi[32]=11, Mod[63,11]=8.

Mathematica

t=Table[0, {100}]; Do[s=Mod[DivisorSigma[1, n], PrimePi[n]]; If[s<101&&t[[s]]==0, t[[s]]=n], {n, 2, 10000}]; t

Crossrefs

Cf. A000203, A000720, A072548, A073721-A073724.

Sequence in context: A298400 A070295 A123483 * A320577 A199805 A053248

Adjacent sequences: A073719 A073720 A073721 * A073723 A073724 A073725

Keyword

nonn

Author

Labos Elemer, Aug 05 2002

Status

approved