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A106742
a(n) = a(a(a(a(a(n - a(n-1)))))) + a(n - a(n-2)) with a(1) = a(2) = 1.
2
1, 1, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13
OFFSET
1,3
COMMENTS
A sixth-order recursion based on A005185.
Different from A087839 - see comments in that entry.
Different from A106733.
LINKS
FORMULA
a(n) = a(a(a(a(a(n -a(n-1)))))) + a(n-a(n-2)) with a(1) = a(2) = 1.
MATHEMATICA
a[n_]:= a[n]= If[n<3, 1, a[a[a[a[a[n - a[n-1]]]]]] + a[n - a[n-2]]];
Table[a[n], {n, 90}]
PROG
(Sage)
@CachedFunction
def a(n): return 1 if (n<3) else a(a(a(a(a(n -a(n-1)))))) + a(n-a(n-2));
[a(n) for n in (1..90)] # G. C. Greubel, Sep 11 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Roger L. Bagula, May 30 2005
EXTENSIONS
Edited by N. J. A. Sloane, Jun 15 2007
STATUS
approved