A100483 a(1) = 2, thereafter a(n) = Sum_{k=1..n-1} floor(a(n-k)/k).

2, 2, 3, 4, 5, 8, 11, 17, 25, 39, 59, 93, 146, 229, 361, 569, 898, 1419, 2243, 3546, 5608, 8869, 14029, 22191, 35105, 55531, 87846, 138967, 219844, 347785, 550183, 870372, 1376909, 2178235, 3445913, 5451350, 8623906, 13642815, 21582611, 34143185

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Maple

a[1]:=2: for n from 2 to 45 do a[n]:=sum(floor(a[n-k]/k), k=1..n-1) od:seq(a[n], n=1..45);

Mathematica

a[n_]:= a[n]= If[n==1, 2, Sum[Floor[a[n-k]/k], {k, n-1}]];
Table[a[n], {n, 50}] (* G. C. Greubel, Apr 05 2023 *)

Prog

(SageMath)
@CachedFunction
def a(n): # a = A100483
    if (n==1): return 2
    else: return sum( (a(n-k)//k) for k in range(1, n) )
[a(n) for n in range(1, 51)] # G. C. Greubel, Apr 05 2023

Crossrefs

Cf. A100482.

Sequence in context: A240575 A176538 A285261 * A182613 A184259 A014535

Adjacent sequences: A100480 A100481 A100482 * A100484 A100485 A100486

Keyword

easy,nonn

Author

Leroy Quet, Nov 22 2004

Extensions

More terms from Emeric Deutsch, Dec 09 2004

Status

approved