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A123265 Fibonacci-Lucas triangle read by rows. 1
2, 1, 2, 3, 3, 2, 4, 8, 5, 2, 7, 15, 15, 7, 2, 11, 30, 35, 24, 9, 2, 18, 56, 80, 66, 35, 11, 2, 29, 104, 171, 170, 110, 48, 13, 2, 47, 189, 355, 407, 315, 169, 63, 15, 2, 76, 340, 715, 932, 832, 532, 245, 80, 17, 2 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

As a Riordan array, this is ((2-x)/(1-x-x^2),x/(1-x-x^2)) . Row sums form A078343, diagonals sums form A014551.

LINKS

Table of n, a(n) for n=0..54.

FORMULA

T(n,k)=T(n-1,k-1)+T(n-1,k)+T(n-2,k), T(0,0)=2, T(1,0)=1, T(n,k)=0 if k<0 or if k>n . T(n,0)=L(n)=A000032(n),Lucas numbers.

EXAMPLE

Triangle begins:

2;

1, 2;

3, 3, 2;

4, 8, 5, 2;

7, 15, 15, 7, 2;

11, 30, 35, 24, 9, 2;

18, 56, 80, 66, 35, 11, 2;

29, 104, 171, 170, 110, 48, 13, 2;

CROSSREFS

Cf. A000032, A099920 ; A007395, A005408, A005563.

Sequence in context: A057475 A024376 A230128 * A104345 A244516 A002339

Adjacent sequences:  A123262 A123263 A123264 * A123266 A123267 A123268

KEYWORD

nonn,tabl

AUTHOR

Philippe Deléham, Nov 07 2006

STATUS

approved

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Last modified April 6 15:41 EDT 2020. Contains 333276 sequences. (Running on oeis4.)