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A048571 Triangle read by rows: T(n,k) = number of distinct prime factors of C(n,k). +0
4
0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 2, 1, 0, 0, 1, 2, 2, 1, 0, 0, 2, 2, 2, 2, 2, 0, 0, 1, 2, 2, 2, 2, 1, 0, 0, 1, 2, 2, 3, 2, 2, 1, 0, 0, 1, 2, 3, 3, 3, 3, 2, 1, 0, 0, 2, 2, 3, 4, 3, 4, 3, 2, 2, 0, 0, 1, 2, 3, 4, 4, 4, 4, 3, 2, 1, 0, 0, 2, 3, 3, 3, 3, 4, 3, 3, 3, 3, 2, 0 (list; table; graph; listen)
OFFSET

0,13

REFERENCES

Pierre Goetgheluck, On prime divisors of binomial coefficients, Math. Comp. 51 (1988), no. 183, 325-329.

LINKS

T. D. Noe, Rows n=0..100 of triangle, flattened

EXAMPLE

Triangle begins:

0

0,0

0,1,0

0,1,1,0

0,1,2,1,0

0,1,2,2,1,0

0,2,2,2,2,2,0

0,1,2,2,2,2,1,0

...

MATHEMATICA

Flatten[Table[b=Binomial[n, k]; Length[FactorInteger[b]], {n, 0, 12}, {k, 0, n}]] - T. D. Noe (noe(AT)sspectra.com), Oct 19 2007

CROSSREFS

Cf. A132896.

Sequence in context: A137867 A111143 A004197 this_sequence A025880 A058755 A128519

Adjacent sequences: A048568 A048569 A048570 this_sequence A048572 A048573 A048574

KEYWORD

nonn,tabl

AUTHOR

njas; edited Oct 06 2007 at the suggestion of T. D. Noe.

EXTENSIONS

Corrected by T. D. Noe (noe(AT)sspectra.com), Oct 19 2007

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Last modified July 19 08:04 EDT 2008. Contains 142098 sequences.


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