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 A196437 #10 Mar 20 2018 19:01:45
%S A196437 1,2,2,3,2,4,2,3,3,3,2,5,2,3,3,3,2,4,2,4,3,3,2,5,2,3,3,3,2,4,2,3,3,3,
%T A196437 2,5,2,3,3,4,2,4,2,3,3,3,2,5,2,3,3,3,2,4,2,3,3,3,2,7,2,3,3,3,2,4,2,3,
%U A196437 3,3,2,5,2,3,3,3,2,4,2,4,3,3,2,5,2,3,3,3,2,4,2,3,3,3,2,5,2,3,3,4,2,4,2,3,3
%N A196437 a(n) = the number of numbers k <= n such that GCQ_A(n, k) = LCQ_A(n, k) = 0 (see definition in comments).
%C A196437 Definition of GCQ_A: The greatest common non-divisor of type A (GCQ_A) of two positive integers a and b (a<=b) is the largest positive non-divisor q of numbers a and b such that 1<=q<=a common to a and b; GCQ_A(a, b) = 0 if no such c exists.
%C A196437 GCQ_A(1, b) = GCQ_A(2, b) = 0 for b >=1. GCQ_A(a, b) = 0 or >= 2.
%C A196437 Definition of LCQ_A: The least common non-divisor of type A (LCQ_A) of two positive integers a and b (a<=b) is the least positive non-divisor q of numbers a and b such that 1<=q<=a common to a and b; LCQ_A(a, b) = 0 if no such c exists.
%C A196437 LCQ_A(1, b) = LCQ_A(2, b) = 0 for b >=1. LCQ_A(a, b) = 0 or >= 2.
%H A196437 Antti Karttunen, <a href="/A196437/b196437.txt">Table of n, a(n) for n = 1..65537</a>
%F A196437 a(n) = n - A196438(n).
%e A196437 For n = 6, a(6) = 4 because there are 4 cases with GCQ_A(6, k) = 0:
%e A196437 GCQ_A(6, 1) = 0, GCQ_A(6, 2) = 0, GCQ_A(6, 3) = 0, GCQ_A(6, 4) = 0, GCQ_A(6, 5) = 4, GCQ_A(6, 6) = 5.
%e A196437 Also there are 4 cases with LCQ_A(6, k) = 0: LCQ_A(6, 1) = 0, LCQ_A(6, 2) = 0, LCQ_A(6, 3) = 0, LCQ_A(6, 4) = 0, LCQ_A(6, 5) = 4, LCQ_A(6, 6) = 4.
%o A196437 (PARI)
%o A196437 GCQ_A(a, b) = { forstep(m=min(a, b)-1, 2, -1, if(a%m && b%m, return(m))); 0; };
%o A196437 A196438(n) = sum(i=3, n, GCQ_A(i, n)>=2);
%o A196437 A196437(n) = (n - A196438(n)); \\ _Antti Karttunen_, Mar 20 2018, based on _Charles R Greathouse IV_'s Aug 26 2017 PARI-program in A196438.
%Y A196437 Cf. A196438, A196439, A196440, A196441, A196442, A196443, A196444.
%K A196437 nonn
%O A196437 1,2
%A A196437 _Jaroslav Krizek_, Nov 26 2011
%E A196437 More terms from _Antti Karttunen_, Mar 20 2018