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A116948 Riordan array ((1+2x^2)/(1-x^3),x). 2
1, 0, 1, 2, 0, 1, 1, 2, 0, 1, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 1, 2, 0, 1, 2, 0, 1, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,4
COMMENTS
Row sums are A117571. Diagonal sums are A117572. Inverse is A116949.
LINKS
FORMULA
Number triangle T(n,k)=2*J(L((n-k+2)/3))[k<=n] where L(j/p) is the Legendre symbol of j and p and J(n)=A001045(n)
EXAMPLE
Triangle begins
1,
0, 1,
2, 0, 1,
1, 2, 0, 1,
0, 1, 2, 0, 1,
2, 0, 1, 2, 0, 1,
1, 2, 0, 1, 2, 0, 1,
0, 1, 2, 0, 1, 2, 0, 1,
2, 0, 1, 2, 0, 1, 2, 0, 1
CROSSREFS
Sequence in context: A333307 A180793 A352523 * A101660 A276771 A062984
KEYWORD
easy,nonn,tabl
AUTHOR
Paul Barry, Mar 29 2006
STATUS
approved

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)