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 A199973 #8 Jan 23 2025 10:25:18 %S A199973 0,0,4,9,12,25,18,28,28,33,28,64,35,47,51,59,45,76,51,81,68,74,61,128, %T A199973 72,88,87,103,78,145,84,119,107,114,101,195,101,129,126,166 %N A199973 a(n) = the sum of LCQ_B(n, k) for 1 <= k <= n (see definition in comments). %C A199973 Definition of LCQ_B: The least common non-divisor of type B (LCQ_B) 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<=b common to a and b; LCQ_B(a, b) = 0 if no such c exists. %C A199973 LCQ_B(a, b) = 0 or >= 2. %F A199973 For n = 6, a(6) = 9 because LCQ_B(6, 1) = 4, LCQ_B(6, 2) = 4, LCQ_B(6, 3) = 4, LCQ_B(6, 4) = 5, LCQ_B(6, 5) = 4, LCQ_B(6, 6) = 4. Sum of results is 25. %Y A199973 Cf.: A196443 (the sum of GCQ_A(n, k) for 1 <= k <= n). %Y A199973 Cf.: A199972 (the sum of GCQ_B(n, k) for 1 <= k <= n). %Y A199973 Cf.: A199971 (the sum of LCQ_A(n, k) for 1 <= k <= n). %Y A199973 Cf.: A199974 (the sum of LCQ_C(n, k) for 1 <= k <= n). %K A199973 nonn %O A199973 1,3 %A A199973 _Jaroslav Krizek_, Nov 26 2011