A199973 a(n) = the sum of LCQ_B(n, k) for 1 <= k <= n (see definition in comments).

0, 0, 4, 9, 12, 25, 18, 28, 28, 33, 28, 64, 35, 47, 51, 59, 45, 76, 51, 81, 68, 74, 61, 128, 72, 88, 87, 103, 78, 145, 84, 119, 107, 114, 101, 195, 101, 129, 126, 166

Offset: 1

Author

Jaroslav Krizek, Nov 26 2011

Keywords

• nonn

Comments

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.

LCQ_B(a, b) = 0 or >= 2.

Crossrefs

Cf.: A196443 (the sum of GCQ_A(n, k) for 1 <= k <= n).

Cf.: A199972 (the sum of GCQ_B(n, k) for 1 <= k <= n).

Cf.: A199971 (the sum of LCQ_A(n, k) for 1 <= k <= n).

Cf.: A199974 (the sum of LCQ_C(n, k) for 1 <= k <= n).

Formula

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.