The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A247165 Numbers m such that m^2 + 1 divides 2^m - 1. 5
 0, 16, 256, 8208, 65536, 649800, 1382400, 4294967296 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Contains 2^(2^k) = A001146(k) for k >= 2. - Robert Israel, Dec 02 2014 a(9) > 10^12. - Hiroaki Yamanouchi, Sep 16 2018 For each n, a(n)^2 + 1 belongs to A176997, and thus a(n) belongs to either A005574 or A135590. - Max Alekseyev, Feb 08 2024 LINKS Table of n, a(n) for n=1..8. EXAMPLE 0 is in this sequence because 0^2 + 1 = 1 divides 2^0 - 1 = 1. MAPLE select(n -> (2 &^ n - 1) mod (n^2 + 1) = 0, [\$1..10^6]); # Robert Israel, Dec 02 2014 MATHEMATICA a247165[n_Integer] := Select[Range[0, n], Divisible[2^# - 1, #^2 + 1] &]; a247165[1500000] (* Michael De Vlieger, Nov 30 2014 *) PROG (Magma) [n: n in [1..100000] | Denominator((2^n-1)/(n^2+1)) eq 1]; (PARI) for(n=0, 10^9, if(Mod(2, n^2+1)^n==+1, print1(n, ", "))); \\ Joerg Arndt, Nov 30 2014 (Python) A247165_list = [n for n in range(10**6) if n == 0 or pow(2, n, n*n+1) == 1] # Chai Wah Wu, Dec 04 2014 CROSSREFS Cf. A247219 (n^2 - 1 divides 2^n - 1), A247220 (n^2 + 1 divides 2^n + 1). Cf. A005574, A135590, A176997. Sequence in context: A001025 A144318 A230142 * A204080 A223433 A223593 Adjacent sequences: A247162 A247163 A247164 * A247166 A247167 A247168 KEYWORD nonn,more AUTHOR Juri-Stepan Gerasimov, Nov 30 2014 EXTENSIONS a(8) from Chai Wah Wu, Dec 04 2014 Edited by Jon E. Schoenfield, Dec 06 2014 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 July 24 18:12 EDT 2024. Contains 374585 sequences. (Running on oeis4.)