A015789 Numbers k such that phi(k) + 10 | sigma(k + 10).

4, 10, 20, 24, 30, 44, 68, 92, 120, 136, 164, 184, 212, 236, 350, 356, 374, 376, 428, 472, 524, 596, 664, 668, 808, 856, 904, 932, 1028, 1076, 1150, 1172, 1192, 1336, 1388, 1410, 1436, 1528, 1532, 1604, 1676, 1864, 1868, 2008, 2012, 2056, 2084

Offset

1,1

Links

Muniru A Asiru, Table of n, a(n) for n = 1..10000

Maple

with(numtheory): select(k->modp(sigma(k+10), phi(k)+10)=0, [$1..2200]); # Muniru A Asiru, Dec 11 2018

Mathematica

Select[Range[2100], Divisible[DivisorSigma[1, # + 10], EulerPhi[#] + 10] &] (* Amiram Eldar, Dec 10 2018 *)

Crossrefs

Cf. A015775, A015781, A015782, A015783, A015784, A015785, A015786, A015788.

Sequence in context: A300018 A268221 A086176 * A145021 A135280 A100436

Adjacent sequences: A015786 A015787 A015788 * A015790 A015791 A015792

Keyword

nonn

Author

Robert G. Wilson v

Extensions

Title corrected by Sean A. Irvine, Dec 10 2018

Status

approved