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 A005733 Least k such that binomial(k,n) has n or more distinct prime factors. (Formerly M1166) 4
 2, 4, 9, 10, 22, 26, 40, 50, 54, 55, 78, 115, 123, 154, 155, 209, 288, 220, 221, 292, 301, 378, 494, 494, 551, 715, 670, 786, 805, 803, 1079, 966, 1190, 1222, 1274, 1274, 1276, 1771, 1836, 1807, 1834, 2147, 2263, 2519, 2519, 3021, 3306, 3306, 3427, 3441, 3445 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Table 3 in Selmer's paper has typos for n = 83, 100 and 117. - T. D. Noe, Apr 05 2007 REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS T. D. Noe, Table of n, a(n) for n=1..1000 Ernst S. Selmer, On the number of prime divisors of a binomial coefficient, Math. Scand. 39 (1976), no. 2, 271-281. MATHEMATICA Table[n=k; b=1; While[n++; b=b*n/(n-k); Length[FactorInteger[b]]

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Last modified October 17 16:42 EDT 2019. Contains 328120 sequences. (Running on oeis4.)