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 A199971 #8 Jan 23 2025 10:25:14 %S A199971 0,0,2,3,7,8,13,17,17,23,23,37,30,37,39,48,40,59,46,62,57,64,56,101, %T A199971 67,78,76,92,73,126,79,108,96,104,96,168,96,119,115,147 %N A199971 a(n) = the sum of LCQ_A(n, k) for 1 <= k <= n (see definition in comments). %C A199971 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 A199971 LCQ_A(1, b) = LCQ_A(2, b) = 0 for b >=1. LCQ_A(a, b) = 0 or >= 2. %e A199971 For n = 6, a(6) = 9 because 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. Sum of results is 8. %Y A199971 Cf.: A196443 (the sum of GCQ_A(n, k) for 1 <= k <= n). %Y A199971 Cf.: A199972 (the sum of GCQ_B(n, k) for 1 <= k <= n). %Y A199971 Cf.: A199973 (the sum of LCQ_B(n, k) for 1 <= k <= n). %Y A199971 Cf.: A199974 (the sum of LCQ_C(n, k) for 1 <= k <= n). %K A199971 nonn %O A199971 1,3 %A A199971 _Jaroslav Krizek_, Nov 26 2011