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A119469 Triangle read by rows: row n gives coefficients (lowest degree first) of P_n(x), where P_0(x) = P_1(x) = 1; P_n(x) = P_{n-1}(x) + x^(n-2)*P_{n-2}(x). 5
1, 1, 2, 2, 1, 2, 1, 2, 2, 1, 2, 2, 1, 2, 1, 2, 2, 3, 1, 2, 2, 1, 2, 2, 3, 3, 3, 2, 2, 1, 2, 1, 2, 2, 3, 3, 5, 3, 4, 3, 3, 1, 2, 2, 1, 2, 2, 3, 3, 5, 5, 5, 5, 5, 4, 5, 3, 2, 2, 1, 2, 1, 2, 2, 3, 3, 5, 5, 7, 6, 7, 6, 8, 6, 7, 5, 5, 3, 3, 1, 2, 2, 1, 2, 2, 3, 3, 5, 5, 7, 8, 8, 8, 10, 9, 10, 10, 10, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

P_n(x) has degree A002620(n).

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..9549 (rows n=0..49 of triangle, flattened).

EXAMPLE

Triangle begins:

1

1

2

2,1

2,1,2

2,1,2,2,1

2,1,2,2,3,1,2

2,1,2,2,3,3,3,2,2,1

2,1,2,2,3,3,5,3,4,3,3,1,2

2,1,2,2,3,3,5,5,5,5,5,4,5,3,2,2,1

MAPLE

P[0]:=1; P[1]:=1; d:=[0, 0]; M:=14; for n from 2 to M do P[n]:=expand(P[n-1]+q^(n-2)*P[n-2]);

lprint(seriestolist(series(P[n], q, M^2))); d:=[op(d), degree(P[n], q)]; od: d;

CROSSREFS

A variant of A127836.

Rows converge to A003113.

Sequence in context: A245977 A082389 A246127 * A127439 A218775 A191971

Adjacent sequences:  A119466 A119467 A119468 * A119470 A119471 A119472

KEYWORD

nonn,tabf

AUTHOR

N. J. A. Sloane, Apr 10 2007

STATUS

approved

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Last modified December 8 04:31 EST 2019. Contains 329850 sequences. (Running on oeis4.)