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A177994 Triangle read by rows, A177990 * A070909 3
1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 3, 1, 2, 1, 1, 1, 4, 1, 3, 1, 2, 1, 1, 4, 1, 3, 1, 2, 1, 1, 1, 5, 1, 4, 1, 3, 1, 2, 1, 1, 5, 1, 4, 1, 3, 1, 2, 1, 1, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Row sums = A101881: (1, 2, 4, 5, 8, 9, 13, 14,...).

LINKS

Reinhard Zumkeller, Rows n = 0..100 of triangle, flattened

FORMULA

As infinite lower triangular matrices, A177990 * A070909

EXAMPLE

First few rows of the triangle =

1;

1, 1;

2, 1, 1;

2, 1, 1, 1;

3, 1, 2, 1, 1;

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

4, 1, 3, 1, 2, 1, 1;

4, 1, 3, 1, 2, 1, 1, 1;

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

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

6, 1, 5, 1, 4, 1, 3, 1, 2, 1, 1;

6, 1, 5, 1, 4, 1, 3, 1, 2, 1, 1, 1;

7, 1, 6, 1, 5, 1, 4, 1, 3, 1, 2, 1, 1;

7, 1, 6, 1, 5, 1, 4, 1, 3, 1, 2, 1, 1, 1;

...

PROG

(Haskell)

a177994 n k = a177994_tabl !! n !! k

a177994_row n = a177994_tabl !! n

a177994_tabl = [1] : [1, 1] : map f a177994_tabl

               where f xs@(x:_) = (x + 1) : 1 : xs

-- Reinhard Zumkeller, Feb 20 2015

CROSSREFS

Cf. A177991 = A070909 * A177990.

Cf. A101881.

Sequence in context: A273619 A034003 A168508 * A179285 A026835 A117975

Adjacent sequences:  A177991 A177992 A177993 * A177995 A177996 A177997

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, May 16 2010

STATUS

approved

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Last modified February 16 19:49 EST 2019. Contains 320167 sequences. (Running on oeis4.)