The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A274564 Numbers k such that sigma(k) == 0 (mod k-9). 2
 10, 11, 15, 19, 24, 33, 105, 33705, 33624064, 2199041081344 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..10. EXAMPLE sigma(10) mod (10 - 9) = 18 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, -9); MATHEMATICA k = -9; Select[Range[Abs@k+1, 10^6], Mod[DivisorSigma[1, #], # + k] == 0 &] (* Vincenzo Librandi, Jul 06 2016 *) PROG (Magma) [n: n in [10..2*10^6] | SumOfDivisors(n) mod (n-9) eq 0 ]; // Vincenzo Librandi, Jul 06 2016 CROSSREFS Cf. A045770, A067702, A088833, A181598, A223608, A274551-A274563, A274565, A274566. Sequence in context: A043801 A043809 A043818 * A112787 A264719 A214792 Adjacent sequences: A274561 A274562 A274563 * A274565 A274566 A274567 KEYWORD nonn,more AUTHOR Paolo P. Lava, Jul 06 2016 EXTENSIONS a(9)-a(10) from Giovanni Resta, Jul 06 2016 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 27 06:20 EDT 2024. Contains 372848 sequences. (Running on oeis4.)