

A151662


The first of three Hofstadter parentschild sequences of Thomas Stoll.


2



1, 0, 2, 1, 3, 3, 4, 4, 5, 7, 7, 8, 7, 10, 8, 10, 10, 11, 10, 13, 11, 13, 13, 14, 16, 16, 17, 16, 19, 17, 19, 19, 20, 21, 21, 22, 22, 23, 24, 24, 25, 24, 27, 25, 27, 27, 28, 30, 30, 31, 30, 33, 31, 33, 33, 34, 36, 36, 37, 36, 39, 37, 39, 39, 40, 39, 42, 40, 42, 42, 43, 45, 45, 46, 45, 48
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OFFSET

0,3


COMMENTS

Define three sequence a, b, c by: a[0]:=1; b[0]:=0; c[0]:=0; for n >= 1, b[n]:=nc[b[n1]]; a[n]:=nb[a[n1]]; c[n]:=na[c[n1]].


LINKS

Table of n, a(n) for n=0..75.
Th. Stoll, On Hofstadter's married functions, Fib. Q., 46/47 (2008/2009), 6267.


MAPLE

M:=130;
a[0]:=1; b[0]:=0; c[0]:=0;
for n from 1 to M do
b[n]:=nc[b[n1]];
a[n]:=nb[a[n1]];
c[n]:=na[c[n1]];
od:
A:=[seq(a[n], n=0..M)];
B:=[seq(b[n], n=0..M)];
C:=[seq(c[n], n=0..M)];


CROSSREFS

See also A151663, A151664. Cf. A005206, A005378, A005379.
Sequence in context: A093068 A097357 A123621 * A049786 A282611 A187498
Adjacent sequences: A151659 A151660 A151661 * A151663 A151664 A151665


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, May 30 2009


STATUS

approved



