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A119492
Composites n not dividing binomial(n,k) for any k to which n is not prime.
0
4, 6, 8, 9, 14, 15, 16, 25, 27, 32, 49, 51, 62, 64, 81, 91, 95, 121, 125, 128, 159, 169, 243, 245, 254, 256, 287, 289, 343, 361, 473, 512, 529, 625, 679, 703, 729, 841, 961, 1022, 1024, 1139, 1199, 1331, 1339, 1369, 1681, 1717, 1849, 1891, 2048, 2051
OFFSET
1,1
EXAMPLE
8 shares factors with 2,4 and 6. bin(8,2)=bin(8,6)=28 and bin(8,4)=70. 8 divides neither 28 nor 70 and is therefore on the list.
MATHEMATICA
For[a = 1, a < 1001, a++; c = 0; If[PrimeQ[a] == True, Continue[]]; For[b = 1, b < a + 1, b++, If[And[GCD[b, a] != 1, Mod[Binomial[a, b], a] == 0], c = c + 1]]; If[c == 0, Print[a]]]
CROSSREFS
Sequence in context: A161760 A213308 A067127 * A285586 A118951 A262389
KEYWORD
nonn
AUTHOR
Neil Fernandez, May 25 2006
STATUS
approved