

A117894


Triangle, row sums = Pell numbers, A000129.


2



1, 1, 1, 1, 2, 2, 1, 3, 3, 5, 1, 4, 4, 8, 12, 1, 5, 5, 11, 19, 29, 1, 6, 6, 14, 26, 46, 70, 1, 7, 7, 17, 33, 63, 111, 169, 1, 8, 8, 20, 40, 80, 152, 268, 408, 1, 9, 9, 23, 47, 97, 193, 367, 647, 985
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OFFSET

1,5


COMMENTS

Rows sum to Pell numbers, A000129. E.g., row 5 sum = (1 + 4 + 4 + 8 + 12) = 12, A000129(4). Deleting the right border gives triangle A117895.


LINKS

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


FORMULA

Rows are composed of difference terms of triangle A117584.


EXAMPLE

First few rows of the triangle are:
1;
1, 1;
1, 2, 2;
1, 3, 3, 5;
1, 4, 4, 8, 12;
1, 5, 5, 11, 19, 29;
1, 6, 6, 14, 26, 46, 70;
1, 7, 7, 17, 33, 63, 111, 169;
...
Row 4 of A117584 = (1, 4, 7, 12). Difference terms (1, 3, 3, 5) = row 4 of A117894.


CROSSREFS

Cf. A000129, A117584, A117895.
Sequence in context: A200779 A286558 A023990 * A177762 A109380 A167754
Adjacent sequences: A117891 A117892 A117893 * A117895 A117896 A117897


KEYWORD

nonn,tabl


AUTHOR

Gary W. Adamson, Mar 30 2006


STATUS

approved



