A024307 a(n) = 2*t(n) + 3*t(n-1) + ... + (k+1)*t(n+1-k), where k=floor((n+1)/2) and t = A023531.

0, 2, 3, 0, 2, 3, 4, 5, 8, 3, 4, 5, 6, 9, 11, 13, 15, 6, 7, 10, 12, 14, 16, 18, 20, 22, 26, 13, 15, 17, 19, 21, 23, 25, 29, 32, 35, 38, 41, 22, 24, 26, 28, 32, 35, 38, 41, 44, 47, 50, 53, 56, 59, 35, 38, 41, 44, 47, 50, 53, 56, 59, 62, 65, 70, 74, 78, 82, 86, 53, 56, 59, 62, 65, 68, 71, 76, 80, 84

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Formula

a(n) = Sum_{k=1..floor((n+1)/2)} (k+1) * A023531(n+1-k). - Sean A. Irvine, Jun 26 2019

Extensions

a(64) corrected and title simplified by Sean A. Irvine, Jun 26 2019