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A156319 Triangle by columns: (1, 2, 0, 0, 0,...) in every column. 1
1, 2, 1, 0, 2, 1, 0, 0, 2, 1, 0, 0, 0, 2, 1, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 2, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Binomial transform of the triangle = A110813.

Eigensequence of the triangle = A001045

Inverse = a triangle with (1, -2, 4, -8, 16,...) in every column.

Triangle T(n,k), 0<=k<=n, given by [2,-2,0,0,0,0,0,0,...] DELTA [1,0,0,0,0,0,0,0,...] where DELTA is the operator defined in A084938 . [From Philippe Deléham, Feb 08 2009]

LINKS

Table of n, a(n) for n=1..55.

FORMULA

Triangle read by rows, T(n,k) = 1 if (n = k); 2 if k = n-1, 0 otherwise.

By columns, (1, 2, 0, 0, 0,...) in every column.

T(n,k)=A097806(n,k)*2^(n-k). [From Philippe Deléham, Feb 08 2009]

G.f.: (-1-2x)*x*y/(x*y-1). - R. J. Mathar, Aug 12 2015

EXAMPLE

First few rows of the triangle =

1;

2, 1;

0, 2, 1;

0, 0, 2, 1;

0, 0, 0, 2, 1;

0, 0, 0, 0, 2, 1;

0, 0, 0, 0, 0, 2, 1;

0, 0, 0, 0, 0, 0, 2, 1;

0, 0, 0, 0, 0, 0, 0, 2, 1;

...

CROSSREFS

Cf. A110813, A001045

Sequence in context: A264034 A058531 A093073 * A251635 A190893 A030204

Adjacent sequences:  A156316 A156317 A156318 * A156320 A156321 A156322

KEYWORD

nonn,tabl,easy

AUTHOR

Gary W. Adamson, Feb 07 2009

STATUS

approved

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Last modified December 16 08:39 EST 2018. Contains 318158 sequences. (Running on oeis4.)