A079719 a(n) = n + floor(Sum_{k

0, 1, 2, 4, 7, 12, 19, 29, 45, 68, 103, 156, 235, 353, 531, 797, 1197, 1796, 2695, 4044, 6067, 9101, 13653, 20480, 30721, 46083, 69125, 103689, 155534, 233302, 349954, 524932, 787399, 1181100, 1771651, 2657477, 3986217, 5979326, 8968990, 13453486

Offset: 0

Author

Henry Bottomley, Feb 17 2003

Keywords

• nonn
• changed

Examples

			a(4) = 4+floor[(0+1+2+4)/2] = 4+floor[7/2] = 4+3 = 7
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000

Programs

Mathematica

nxt[{n_,t_,a_}]:=Module[{c=n+1+Floor[t/2]},{n+1,t+c,c}]; NestList[nxt,{0,0,0},40][[All,3]] (* Harvey P. Dale, Aug 01 2021 *)

Formula

a(n)=A073941(n+4)-2 (and appears to be A005428(n+1)) =round[1.82505431574536323...*1.5^n - 2]