A063892 a(1) = a(2) = a(3) = 1, a(n) = a(n-a(n-2))+a(n-a(n-3)) for n>3.

1, 1, 1, 2, 4, 6, 5, 3, 3, 9, 6, 4, 7, 12, 9, 5, 7, 10, 16, 16, 10, 12, 12, 16, 14, 21, 13, 17, 8, 14, 24, 26, 19, 12, 8, 23, 22, 23, 12, 17, 18, 28, 35, 26, 16, 22, 34, 47, 22, 6, 10, 36, 69, 36

Offset

1,4

Comments

Undefined for n>54 since a(53)=69>=55.

Links

Table of n, a(n) for n=1..54.

Example

a(7) = a(7-a(5))+a(7-a(4)) = a(7-4)+a(7-2) = a(3)+a(5) = 1+4 = 5.

Maple

#Q(r, s) with initial values 1, 1, 1, ..., from N. J. A. Sloane, Apr 15 2014
r:=2; s:=3;
a:=proc(n) option remember; global r, s;
if n <= s then 1
else
    if (a(n-r) <= n) and (a(n-s) <= n) then
    a(n-a(n-r))+a(n-a(n-s));
    else lprint("died with n =", n); return (-1);
    fi;
fi; end;
[seq(a(n), n=1..54)];

Crossrefs

Cf. A005185, A046700, A063882, A226222.

See A064714 for a variant which does not die.

Sequence in context: A242796 A298527 A071288 * A353650 A254763 A023825

Adjacent sequences: A063889 A063890 A063891 * A063893 A063894 A063895

Keyword

fini,full,nonn

Author

Henry Bottomley, Aug 29 2001

Status

approved