

A217536


Square array read by antidiagonals, where the top row is the nonnegative integers and the other numbers are the sum of the neighbors in the preceding row.


0



0, 1, 1, 2, 3, 4, 3, 6, 10, 14, 4, 9, 18, 32, 46, 5, 12, 27, 55, 101, 147, 6, 15, 36, 81, 168, 315, 462, 7, 18, 45, 108, 244, 513, 975, 1437, 8, 21, 54, 135, 324, 736, 1564, 2539, 3976, 9, 24, 63, 162, 405, 973, 2222, 4761, 8737, 12713
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OFFSET

1,4


COMMENTS

Each number in the top row of the array is determined by the predefined sequence (in this case, the nonnegative integers). Each number in lower rows is the sum of the numbers vertically or diagonally above it (so, the number at the left end of each row is the sum of two numbers, and all other numbers the sum of three).


LINKS

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


FORMULA

T(m+1,n) = sum(T(m,k), kn <= 1) (and T(0,n)=n), m, n >= 0.  M. F. Hasler, Oct 09 2012


EXAMPLE

The array starts:
0 1 2 3
1 3 6 9
4 10 18 27
14 32 55 81


CROSSREFS

Sequence in context: A103634 A255046 A098596 * A058267 A048259 A324150
Adjacent sequences: A217533 A217534 A217535 * A217537 A217538 A217539


KEYWORD

nonn,tabl


AUTHOR

WG Zeist, Oct 06 2012


STATUS

approved



