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A015789
Numbers k such that phi(k) + 10 | sigma(k + 10).
1
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
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 *)
KEYWORD
nonn
EXTENSIONS
Title corrected by Sean A. Irvine, Dec 10 2018
STATUS
approved