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A096007
Scan Pascal's triangle (A007318) from left to right, record smallest prime factor of each entry.
0
2, 3, 3, 2, 2, 2, 5, 2, 2, 5, 2, 3, 2, 3, 2, 7, 3, 5, 5, 3, 7, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 3, 2, 3, 2, 2, 2, 2, 2, 3, 2, 11, 5, 3, 2, 2, 2, 2, 3, 5, 11, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 13, 2, 2, 5, 3, 2, 2, 3, 5, 2, 2, 13, 2, 7, 2, 7, 2, 3, 2, 3, 2, 7, 2, 7, 2, 3, 3, 5, 3, 3, 5, 3, 3, 5, 3, 3, 5, 3
OFFSET
1,1
EXAMPLE
n Pascal's Triangle
1 1
2 1 2 1
3 1 3 3 1
4 1 4 6 4 1
so 2, 2, 2 = smallest prime factors of row 4 = entries position 4, 5, 6 in the sequence.
PROG
(PARI) \Smallest prime factors of numbers in Pascal's triangle. pascal(n) = { local(x, y, z, f, z1); for(x=1, n, for(y=1, x-1, z=binomial(x, y); f=Vec(factor(z)); z1=f[1][1]; print1(z1", ") ); ) }
CROSSREFS
Cf. A007318.
Sequence in context: A011154 A048466 A096838 * A269043 A309952 A059252
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, Jul 25 2004
STATUS
approved