A274563
Numbers k such that sigma(k) == 0 (mod k+9).
Original entry on oeis.org
15, 208, 6976, 8415, 31815, 351351, 2077696, 20487159, 159030135, 536559616, 2586415095, 137433972736, 2199003332608
Offset: 1
sigma(15) mod (15 + 9) = 24 mod 24 = 0.
-
Select[Range[10^6], Mod[DivisorSigma[1, #], # + 9] == 0 &] (* Michael De Vlieger, Jul 06 2016 *)
A274564
Numbers k such that sigma(k) == 0 (mod k-9).
Original entry on oeis.org
6, 7, 8, 10, 11, 15, 19, 24, 33, 105, 33705, 33624064, 2199041081344
Offset: 1
sigma(10) mod (10 - 9) = 18 mod 1 = 0.
Cf.
A045770,
A067702,
A088833,
A181598,
A274551,
A274552,
A274553,
A274554,
A274556,
A274557,
A274558,
A274559,
A274560,
A274561,
A274562,
A274563,
A274565,
A274566.
-
[n: n in [10..2*10^6] | SumOfDivisors(n) mod (n-9) eq 0 ]; // Vincenzo Librandi, Jul 06 2016
-
k = -9; Select[Range[Abs@k+1, 10^6], Mod[DivisorSigma[1, #], # + k] == 0 &] (* Vincenzo Librandi, Jul 06 2016 *)
-
isok(k) = (k!=9) && (Mod(sigma(k), k-9) == 0); \\ Michel Marcus, May 30 2025
A274559
Numbers k such that sigma(k) == 0 (mod k+7).
Original entry on oeis.org
8, 272, 7232, 30848, 516608, 134094848, 2146992128, 35184309174272
Offset: 1
sigma(8) mod (8+7) = 15 mod 15 = 0.
Cf.
A045770,
A067702,
A088833,
A181598,
A274551,
A274552,
A274553,
A274554,
A274556,
A274557,
A274558,
A274560,
A274561,
A274562,
A274563,
A274564,
A274565,
A274566.
-
Select[Range[10^6], Mod[DivisorSigma[1, #], # + 7] == 0 &] (* Michael De Vlieger, Jul 05 2016 *)
A274565
Numbers k such that sigma(k) == 0 (mod k+10).
Original entry on oeis.org
14, 176, 1376, 3230, 3770, 6848, 114256, 125696, 544310, 561824, 740870, 2075648, 4199030, 4607296, 8436950, 33468416, 134045696, 199272950, 624032630, 1113445430, 1550860550, 85905593344, 2199001235456, 35184284008448
Offset: 1
sigma(14) mod (14 + 10) = 24 mod 24 = 0.
Cf.
A045770,
A067702,
A088833,
A181598,
A274551,
A274552,
A274553,
A274554,
A274556,
A274557,
A274558,
A274559,
A274560,
A274561,
A274562,
A274563,
A274564,
A274566.
-
[n: n in [1..2*10^6] | SumOfDivisors(n) mod (n+10) eq 0 ]; // Vincenzo Librandi, Jul 06 2016
-
k = 10; Select[Range[Abs@k+1, 10^6], Mod[DivisorSigma[1, #], # + k] == 0 &] (* Vincenzo Librandi, Jul 06 2016 *)