

A082793


A tribonacci triangle in which the top two northeast and southeast diagonals consist of tribonacci numbers.


2



1, 1, 1, 2, 1, 2, 4, 2, 2, 4, 7, 4, 4, 4, 7, 13, 7, 8, 8, 7, 13, 24, 13, 14, 16, 14, 13, 24, 44, 24, 26, 28, 28, 26, 24, 44
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OFFSET

1,4


COMMENTS

Uses a Hosoyalike format except that the latter has the Fibonacci recursion. This triangle uses the tribonacci recursion such that every interior number can be obtained by adding the 3 previous numbers, on its diagonal.


REFERENCES

Thomas Koshy, <"Fibonacci and Lucas Numbers with Applications">John Wiley and Sons, 2001, Chapter 15, pages 187195, "Hosoya's Triangle".


LINKS

Table of n, a(n) for n=1..36.


FORMULA

T(n, j) = T(n1, j) + T(n2, j) + T(n3, j); (every interior number can be obtained by adding the three previous numbers, on its diagonal.)


EXAMPLE

T(7,3) = 14 = (8 + 4 + 2) = T(6,3) + T(5,3) + T(4,3).


CROSSREFS

Cf. A000073, tribonacci numbers, A058071, Hosoya's triangle.
Sequence in context: A145173 A270594 A270706 * A114929 A247321 A152251
Adjacent sequences: A082790 A082791 A082792 * A082794 A082795 A082796


KEYWORD

nonn


AUTHOR

Gary W. Adamson, May 24 2003


STATUS

approved



