A056549 a(n) = Sum_{k>=1} round(n/k) where round(1/2)=1.
0, 2, 5, 9, 12, 17, 21, 25, 30, 35, 39, 45, 49, 54, 60, 66, 69, 75, 82, 86, 92, 98, 102, 110, 114, 120, 126, 132, 138, 144, 150, 154, 161, 169, 173, 181, 186, 190, 198, 206, 210, 217, 223, 229, 235, 243, 249, 255, 261, 266, 275, 281, 285, 295, 301, 307, 313, 319
Offset: 0
Formula
Conjecture: a(n) = n + Sum_{k=1..n} floor(n/k + 1/2) = n + A077024(n). - Ridouane Oudra, Apr 29 2019
Comments