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A173564 a(n) = a(n-1) + a(n-2) - [a(n-3)/4] - [a(n-4)/2] - [a(n-5)/4]. 2
1, 1, 2, 3, 5, 8, 12, 18, 26, 36, 50, 68, 92, 124, 165, 220, 291, 385, 508, 670, 882, 1161, 1526, 2005, 2633, 3457, 4536, 5952, 7807, 10239, 13426, 17604, 23080, 30258, 39665, 51995, 68155, 89335, 117096, 153480, 201168, 263669, 345586, 452949, 593664, 778091, 1019808, 1336613, 1751830, 2296030, 3009281 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

The limiting ratio a(n+1)/a(n) at the 500th iteration is:1.3106397635502627

LINKS

Table of n, a(n) for n=0..50.

FORMULA

a(n)=a(n-1)+a(n-2)-Floor[a(n-3)/4]-Floor[a(n-4)/2]-Floor[a(n-5)/4]

MATHEMATICA

f[-3] = 0; f[-2] = 0; f[-1] = 0; f[0] = 1; f[1] = 1;

f[n_] := f[n] = f[n - 1] + f[n - 2] - Floor[f[n - 3]/

4] - Floor[f[n - 4]/2] - Floor[f[n - 5]/4]

Table[f[n], {n, 0, 50}]

CROSSREFS

Cf. A173538

Sequence in context: A252864 A039899 A039901 * A121946 A241823 A058984

Adjacent sequences:  A173561 A173562 A173563 * A173565 A173566 A173567

KEYWORD

nonn

AUTHOR

Roger L. Bagula, Nov 23 2010

STATUS

approved

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Last modified July 21 20:57 EDT 2017. Contains 289648 sequences.