

A130826


a(n) is the smallest number such that twice the number of divisors of (a(n)n)/3 gives the nth term in the first differences of the sequence produced by the FlaviusJosephus sieve, A000960.


1



4, 8, 15, 16, 23, 42, 55, 200, 81, 46, 119, 192, 205, 196622, 12303, 88, 449, 558, 127, 1748, 786453, 58, 2183, 3096, 1105, 786458, 12582939, 568, 2189, 2730, 9247, 572, 8673, 3106, 2195, 8676, 145, 110630, 3819, 2200, 786473, 20202, 79, 7604, 7077933
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OFFSET

1,1


COMMENTS

The first six terms in the sequence are those from the T.V. show Lost.


LINKS

Table of n, a(n) for n=1..45.
M. E. Andersson, Das Flaviussche Sieb, Acta Arith., 85 (1998), 301307.
V. Gardiner, R.Lazarus, N. Metropolis and S. Ulam, On certain sequences of integers defined by sieves, Math. Mag., 29 (1955), 117119.


EXAMPLE

a(8)=200 because the 8th term in A056526 is 14. Half of that is 7. The smallest number with seven divisors is 64 and 64*3 + 8 = 200.


CROSSREFS

Cf. A000960, A056526, A104101.
Cf. A005179. [Alois P. Heinz, Nov 27 2009]
Sequence in context: A272346 A214440 A104101 * A312708 A312709 A312710
Adjacent sequences: A130823 A130824 A130825 * A130827 A130828 A130829


KEYWORD

dumb,nonn


AUTHOR

Stephen Casey (hexomino(AT)gmail.com), Jul 17 2007


EXTENSIONS

Corrected and extended by Alois P. Heinz, Nov 27 2009


STATUS

approved



