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.
%I A249104 #27 Jan 05 2025 19:51:40
%S A249104 8,11,12,13,16,17,18,19,21,22,23,24,26,28,29,31,32,33,34,36,37,38,39,
%T A249104 40,41,42,43,44,46,47,48,49,51,52,53,54,55,56,57,58,59,60,61,62,63,64,
%U A249104 65,66,67,68,69,71,72,73,74,76,77,78,79,80,82,83,84,85,86,87
%N A249104 Defective numbers: A complete residue system mod a(n) does not exist in the Fibonacci sequence.
%C A249104 Every multiple of a member is a member.
%C A249104 Every integer 2^r*m (r>2, m odd) is a member.
%C A249104 Every prime p congruent 1, 9, 11, 13, 17, 19 (mod 20) is a member (see reference).
%H A249104 A. P. Shah, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/6-2/shah.pdf">Fibonacci Sequence Modulo m</a>, Fibonacci Quarterly, Vol.6, No.2 (1968), 139-141.
%F A249104 A066853(a(n)) < a(n) in ascending order.
%e A249104 16 is a member because A066853(16) = 11 < 16.
%o A249104 (PARI) isok(k) = {if(k<8, return(0)); my(v=List([1, 2])); while(v[#v]!=1 || v[#v-1]!=0, listput(v, (v[#v]+v[#v-1])%k)); #Set(v)<k; } \\ _Jinyuan Wang_, Mar 20 2020
%Y A249104 Cf. A000045, A066853.
%Y A249104 Complement of A079002. - _Jeppe Stig Nielsen_, Dec 11 2017
%K A249104 nonn
%O A249104 1,1
%A A249104 _Franz Vrabec_, Oct 21 2014
%E A249104 More terms from _Jinyuan Wang_, Mar 20 2020