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A080218 Monotonically increasing sequence such that every positive integer n appears if and only if d(n) doesn't (d(n)=number of divisors of n, A000005). +0
1
3, 5, 6, 7, 8, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 26, 27, 29, 31, 33, 34, 35, 36, 37, 38, 39, 41, 43, 46, 47, 51, 53, 55, 57, 58, 59, 60, 61, 62, 65, 67, 69, 71, 72, 73, 74, 77, 79, 82, 83, 84, 85, 86, 87, 89, 90, 91, 93, 94, 95, 96, 97, 100, 101, 103, 106, 107, 108, 109 (list; graph; listen)
OFFSET

1,1

REFERENCES

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 840.

LINKS

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, December 1972 [alternative scanned copy].

EXAMPLE

d(1)=1 and d(2)=2; therefore neither are included. Members include 3 (2 divisors), 6 (4 divisors) and 60 (12 divisors); other nonmembers include 4 (3 divisors), 12 (6 divisors), and 5040 (60 divisors).

CROSSREFS

Sequence in context: A039063 A114978 A138891 this_sequence A080651 A047330 A093511

Adjacent sequences: A080215 A080216 A080217 this_sequence A080219 A080220 A080221

KEYWORD

easy,nonn

AUTHOR

Matthew Vandermast (ghodges14(AT)comcast.net), Mar 16 2003

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Last modified November 21 14:49 EST 2008. Contains 150807 sequences.


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