A015973 Positive integers n such that n | (3^n + 2).
1, 5, 77, 278377, 3697489, 219596687717, 56865169816619
Offset: 1
Crossrefs
Extensions
a(1)=1 prepended and a(6)-a(7) added by Max Alekseyev, Aug 04 2011
This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
3 == 5 (mod 1), so 1 is a term; 9 == 5 (mod 2), so 2 is a term.
Select[Range[10^7], PowerMod[3, #, #] == Mod[5, #] &] (* Michael De Vlieger, Sep 26 2016 *)
isok(n) = Mod(3, n)^n == Mod(5, n); \\ Michel Marcus, Sep 17 2016
A276740_list = [1,2,4]+[n for n in range(5,10**6) if pow(3,n,n) == 5] # Chai Wah Wu, Oct 04 2016
3 == 7 mod 1, so 1 is a term; 9 == 7 mod 2, so 2 is a term.
isok(n) = Mod(3, n)^n == 7; \\ Michel Marcus, Oct 06 2016
3^14 + 5 = 4782974 = 14 * 341641, so 14 is a term.
is(n)=Mod(3,n)^n==-5; \\ Joerg Arndt, Oct 09 2016
A277288_list = [1,2]+[n for n in range(3,10**6) if pow(3,n,n)==n-5] # Chai Wah Wu, Oct 09 2016
def A277288_list(search_limit): n, t, r = 1, Integer(3), [1] while n < search_limit: n += 1 t *= 3 if n.divides(t+5): r.append(n) return r # Peter Luschny, Oct 10 2016
3 == 11 mod 1, so 1 is a term. 9 == 11 mod 2, so 2 is a term.
k = 3; lst = {1, 2}; While[k < 12000000001, If[ PowerMod[3, k, k] == 11, AppendTo[lst, k]]; k++]; lst (* Robert G. Wilson v, Oct 08 2016 *)
3^10 + 11 = 59060 = 10 * 5906, so 10 is a term.
is(n)=Mod(3,n)^n==-11; \\ Joerg Arndt, Oct 10 2016
A277340_list = [1,2,4,7,10]+[n for n in range(11,10**6) if pow(3,n,n)==n-11] # Chai Wah Wu, Oct 11 2016
[n+1: n in [0..5000000] | Modexp(3,n+2,n+1) eq n];
filter:= m -> 3 &^ (m+1) + 1 mod m = 0: select(filter, [$1..10^7]); # Robert Israel, Oct 30 2019
isok(m) = Mod(3, m)^(m+1) == -1; \\ Michel Marcus, Oct 10 2019
isok(n) = Mod(3, n)^n == Mod(6, n);
isok(n) = Mod(3, n)^n == Mod(8, n);
Comments