A070868 - OEIS

This site is supported by donations to The OEIS Foundation.

A070868

a(1) = a(2) = 1; a(n) = a(a(n-1)) + a(n+1 - 2*a(n-1)).

1, 1, 2, 2, 2, 3, 3, 4, 3, 4, 4, 4, 5, 4, 6, 5, 6, 6, 7, 6, 7, 6, 7, 7, 7, 8, 8, 9, 7, 9, 7, 10, 8, 11, 8, 11, 9, 10, 10, 11, 10, 11, 10, 11, 11, 11, 12, 11, 13, 12, 13, 13, 14, 12, 14, 11, 15, 13, 16, 12, 14, 12, 15, 14, 14, 14, 15, 16, 15, 16, 16, 15, 17, 16, 16, 16, 16, 17, 17, 18 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,3`
	REFERENCES	`S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 129.`
	LINKS	`Eric Weisstein's World of Mathematics, Wolfram Sequences` `Index entries for Hofstadter-type sequences` `Nick Hobson, Python program for this sequence`
	MATHEMATICA	`a[1] = a[2] = 1; a[n_] := a[n] = a[ a[n - 1]] + a[n + 1 - 2*a[n - 1]]; Table[ a[n], {n, 1, 80}]`
	CROSSREFS	`Sequence in context: A177903 A107325 A003050 * A155216 A064144 A077105` `Adjacent sequences: A070865 A070866 A070867 * A070869 A070870 A070871`
	KEYWORD	`nonn,easy`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com), May 19 2002`
	EXTENSIONS	`More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), May 20 2002`

Content is available under The OEIS End-User License Agreement .

Last modified February 17 18:34 EST 2012. Contains 206074 sequences.