A079686 Start with 0; at n-th step, write down what is in the sequence so far.

0, 1, 0, 1, 1, 2, 0, 1, 2, 3, 1, 3, 0, 2, 3, 2, 2, 5, 1, 4, 0, 1, 5, 1, 4, 3, 3, 5, 2, 6, 1, 5, 0, 1, 6, 4, 5, 2, 4, 5, 3, 6, 2, 9, 1, 6, 0, 1, 9, 0, 8, 0, 7, 4, 6, 6, 5, 4, 4, 6, 3, 8, 2, 11, 1, 7, 0, 1, 11, 0, 10, 2, 9, 2, 8, 2

Offset

0,6

Comments

Start with the highest value currently in the sequence and count down to zero.

Links

Nathaniel Johnston, Table of n, a(n) for n = 0..10000

Example

After the sequence is "0, 1, 0, 1, 1, 2, 0", we see one "2", three "1"s, and three "0"s, so we add 1, 2, 3, 1, 3, 0 to the sequence.

Mathematica

s={0}; Do[s=Flatten[{s, {Count[s, #], #}&/@Range[Max[s], 0, -1]}], {60}]; s (* Peter J. C. Moses, Mar 21 2013 *)

Prog

(MATLAB) a=[0]; c=2; d=2; for j=1:7 for k=max(a):-1:0 a(c)=size(find(a(1:d-1)==k), 2); a(c+1)=k; c=c+2; end; d=c; end; a' % Nathaniel Johnston, Apr 25 2011

Crossrefs

Cf. A005150. For other versions see A051120, A079668, A055186.

Sequence in context: A071512 A263136 A080018 * A005813 A049262 A374748

Adjacent sequences: A079683 A079684 A079685 * A079687 A079688 A079689

Keyword

nonn,easy,base

Author

N. J. A. Sloane, Jan 26 2003

Extensions

a(13)-a(75) from Nathaniel Johnston, Apr 25 2011

Status

approved