login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A130074 Nonprimes n such that n divides 5^n - 3^n - 2^n = A130072(n). 4
1, 4, 6, 8, 9, 12, 15, 16, 18, 24, 25, 27, 32, 36, 44, 45, 48, 54, 64, 72, 75, 81, 95, 96, 108, 125, 128, 133, 135, 144, 162, 175, 192, 216, 225, 243, 256, 264, 288, 324, 325, 361, 375, 384, 405, 432, 475, 486, 512, 561, 576, 594, 618, 625, 648, 675, 704, 729, 768 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Numbers n such that n divides A130072(n) are listed in A130073(n) = {1,2,3,4,5,6,7,8,9,11,12,13,15,16,17,18,19,23,24,25,27,29,31,32,36,37,41,43,...}, which includes all primes. a(n) includes nonprimes in A130073(n). p^(k+1) divides A130072(p^k) for prime p = {2,3,5,19} = A130076(n) and all k>0. It appears that a(n) includes all powers p^k of primes p = {2,3,5,19} for k>1 and all powers of numbers of the form 2^k*3^m, 3^k*5^m, 5^k*19^m.

LINKS

Table of n, a(n) for n=1..59.

MATHEMATICA

Select[Range[10000], !PrimeQ[ # ]&&IntegerQ[(PowerMod[5, #, # ]-PowerMod[3, #, # ]-PowerMod[2, #, # ])/# ]&]

CROSSREFS

Cf. A130072, A130073, A130075, A130076.

Sequence in context: A100425 A258614 A269131 * A304242 A067012 A157942

Adjacent sequences:  A130071 A130072 A130073 * A130075 A130076 A130077

KEYWORD

nonn

AUTHOR

Alexander Adamchuk, May 06 2007

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 5 08:02 EDT 2020. Contains 335464 sequences. (Running on oeis4.)