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A027052 Triangular array T read by rows: T(n,0)=T(n,2n)=1 for n >= 0, T(n,1)=0 for n >= 1, T(n,2)=1 for n >= 2 and for n >= 3, T(n,k)=T(n-1,k-3)+T(n-1, k-2)+T(n-1,k-1) for 3<=k<=2n-1. T(n,k)=0 for k<0 or k>2n. 39
1, 1, 0, 1, 1, 0, 1, 2, 1, 1, 0, 1, 2, 3, 4, 1, 1, 0, 1, 2, 3, 6, 9, 8, 1, 1, 0, 1, 2, 3, 6, 11, 18, 23, 18, 1, 1, 0, 1, 2, 3, 6, 11, 20, 35, 52, 59, 42, 1, 1, 0, 1, 2, 3, 6, 11, 20, 37, 66, 107, 146, 153, 102, 1, 1, 0, 1, 2, 3, 6, 11, 20, 37, 68, 123, 210 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,8

COMMENTS

The following sequences all have the same parity: A004737, A006590, A027052, A071028, A071797, A078358, A078446. - Jeremy Gardiner, Mar 16 2003

LINKS

Table of n, a(n) for n=0..75.

FORMULA

A001590(k+1) = T(n,k) if 0<=k<=n. - Michael Somos, Jun 01 2014

EXAMPLE

Triangle T(n,k) for 0<=k<=2n:

1

1, 0, 1

1, 0, 1, 2, 1

1, 0, 1, 2, 3, 4, 1

1, 0, 1, 2, 3, 6, 9, 8, 1

CROSSREFS

Cf. A001590, a tribonacci sequence.

Cf. A160999 (row sums), A005408 (row lengths).

Sequence in context: A153764 A294509 A059571 * A194438 A144409 A131257

Adjacent sequences:  A027049 A027050 A027051 * A027053 A027054 A027055

KEYWORD

nonn,tabf

AUTHOR

Clark Kimberling

EXTENSIONS

Offset and keyword:tabl corrected by R. J. Mathar, Jun 01 2009

STATUS

approved

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Last modified November 13 13:15 EST 2018. Contains 317149 sequences. (Running on oeis4.)