A210994 - OEIS

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A210994

Numbers n such that A000005(n) <> 4.

1, 2, 3, 4, 5, 7, 9, 11, 12, 13, 16, 17, 18, 19, 20, 23, 24, 25, 28, 29, 30, 31, 32, 36, 37, 40, 41, 42, 43, 44, 45, 47, 48, 49, 50, 52, 53, 54, 56, 59, 60, 61, 63, 64, 66, 67, 68, 70, 71, 72, 73, 75, 76, 78, 79, 80, 81, 83, 84, 88, 89, 90, 92, 96

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..64.

EXAMPLE

6 is not in the sequence because 6 has four divisors: 1, 2, 3, 6.

MATHEMATICA

Select[Range[100], DivisorSigma[0, #]!=4&] (* Harvey P. Dale, Jan 07 2013 *)

CROSSREFS

Complement of A030513. Column 4 of A210976.

Cf. A018252, A213367.

Sequence in context: A262691 A117290 A286972 * A331593 A319237 A331230

Adjacent sequences: A210991 A210992 A210993 * A210995 A210996 A210997

KEYWORD

nonn

AUTHOR

Omar E. Pol, Aug 11 2012

STATUS

approved