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 A199974 #8 Jan 23 2025 10:25:23 %S A199974 2,6,7,14,12,25,18,28,28,33,28,64,35,47,51,59,45,76,51,81,68,74,61, %T A199974 128,72,88,87,103,78,145,84,119,107,114,101,195,101,129,126,166 %N A199974 a(n) = the sum of LCQ_C(n, k) for 1 <= k <= n (see definition in comments). %C A199974 Definition of LCQ_C: The least common non-divisor of type C (LCQ_C) 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 common to a and b. LCQ_C(a, b) >= 2. %e A199974 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 A199974 Cf.: A196443 (the sum of GCQ_A(n, k) for 1 <= k <= n). %Y A199974 Cf.: A199972 (the sum of GCQ_B(n, k) for 1 <= k <= n). %Y A199974 Cf.: A199971 (the sum of LCQ_A(n, k) for 1 <= k <= n). %Y A199974 Cf.: A199973 (the sum of LCQ_B(n, k) for 1 <= k <= n). %K A199974 nonn %O A199974 1,1 %A A199974 _Jaroslav Krizek_, Nov 26 2011