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A274562
Numbers k such that sigma(k) == 0 (mod k-8).
2
9, 10, 11, 12, 14, 17, 38, 92, 168, 170, 248, 752, 988, 2528, 2808, 8648, 12008, 34688, 63248, 117808, 526688, 531968, 820808, 1292768, 1495688, 2095208, 2112512, 3477608, 4495808, 8419328, 12026888, 13192768, 16102808, 26347688, 29322008, 33653888, 169371008, 173631608, 293947648, 537116672, 883927808, 2147975168, 2493705728, 5556840416, 13092865928, 42783299288, 69662739968, 80999455688, 217898810368, 546409576448, 1020401174528, 1081071376208, 1282330216448, 1473186024448, 1577975316488, 1608005456768
OFFSET
1,1
EXAMPLE
sigma(9) mod (9 - 8) = 13 mod 1 = 0.
MAPLE
with(numtheory); P:=proc(q, h) local n; for n from 1 to q do
if n+h>0 then if type(sigma(n)/(n+h), integer) then print(n); fi; fi; od; end: P(10^9, -8);
MATHEMATICA
Select[Range[9, 10^6], Mod[DivisorSigma[1, #], # - 8] == 0 &] (* Michael De Vlieger, Jul 05 2016 *)
KEYWORD
nonn
AUTHOR
Paolo P. Lava, Jul 05 2016
EXTENSIONS
a(30)-a(56) from Giovanni Resta, Jul 05 2016
STATUS
approved