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A140822 Triangle t(n,m) = binomial(n,gcd(n,m)) read by rows, 0<=m<=n. 0
1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 6, 4, 1, 1, 5, 5, 5, 5, 1, 1, 6, 15, 20, 15, 6, 1, 1, 7, 7, 7, 7, 7, 7, 1, 1, 8, 28, 8, 70, 8, 28, 8, 1, 1, 9, 9, 84, 9, 9, 84, 9, 9, 1, 1, 10, 45, 10, 45, 252, 45, 10, 45, 10, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

Row sums are 1, 2, 4, 8, 16, 22, 64, 44, 160, 224, 474,...

LINKS

Table of n, a(n) for n=0..65.

FORMULA

t(n,m) = A007318(n,A109004(n,m)).

EXAMPLE

1;

1, 1;

1, 2, 1;

1, 3, 3, 1;

1, 4, 6, 4, 1;

1, 5, 5, 5, 5, 1;

1, 6, 15, 20, 15, 6, 1;

1, 7, 7, 7, 7, 7, 7, 1;

1, 8, 28, 8, 70, 8, 28, 8, 1;

1, 9, 9, 84, 9, 9, 84, 9, 9, 1;

1, 10, 45, 10, 45, 252, 45, 10, 45, 10, 1;

MATHEMATICA

a = Table[Table[Binomial[n, GCD[n, m]], {m, 0, n}], {n, 0, 10}]; Flatten[a]

CROSSREFS

Sequence in context: A034930 A095142 A180171 * A212954 A089239 A223968

Adjacent sequences:  A140819 A140820 A140821 * A140823 A140824 A140825

KEYWORD

nonn,easy,tabl

AUTHOR

Roger L. Bagula and Gary W. Adamson, Jul 16 2008

EXTENSIONS

Offset corrected. - R. J. Mathar, Nov 07 2011

STATUS

approved

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Last modified December 8 22:51 EST 2016. Contains 278957 sequences.