cp's OEIS Frontend

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.

A335721 Integers m such that A014448(m) == 5 (mod m).

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%I A335721 #18 Jun 20 2020 02:12:15
%S A335721 1,213,85887,974943,2463831,3952791,217643749,286354743,874273639,
%T A335721 14029228621
%N A335721 Integers m such that A014448(m) == 5 (mod m).
%C A335721 Inspired by A335670.
%C A335721 All terms greater than 1 are odd and composite. - _Michel Marcus_, Jun 19 2020
%t A335721 Select[Range[10^5], Divisible[LucasL[3#] - 5, #] &] (* _Amiram Eldar_, Jun 19 2020 *)
%o A335721 (PARI) f(n) = my(w=quadgen(5)); (1+2*w)^n + (3-2*w)^n; \\ A014448
%o A335721 isok(m) = (m%2) && (m>1) && !isprime(m) && ((f(m) % m) == 5); \\ _Michel Marcus_, Jun 19 2020
%Y A335721 Cf. A014448, A335670, A335722.
%K A335721 nonn,more
%O A335721 1,2
%A A335721 _Chai Wah Wu_, Jun 18 2020
%E A335721 a(7)-a(10) from _Giovanni Resta_, Jun 19 2020