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A173040
Single primes having no representation of the form n-+d(n), where d(n) is the number of divisors of n.
0
67, 79, 131, 167, 379, 401, 439, 479, 487, 499, 503, 647, 739, 743, 761, 773, 863, 887, 941, 967, 971, 1109, 1283, 1307, 1373, 1459, 1571, 1583, 1663, 1733, 1867, 2039, 2137, 2207, 2251, 2377, 2393, 2539, 2543, 2579, 2617, 2663, 2699, 2741, 2749, 2797, 2833, 2861, 2957, 3037, 3041, 3079, 3083, 3191
OFFSET
1,1
MATHEMATICA
nn=10000; p=Select[Union[Flatten[Table[d=DivisorSigma[0, n]; {n-d, n+d}, {n, nn}]]], PrimeQ]; Complement[Prime[Range[PrimePi[p[[-1]]]]], p]
CROSSREFS
Cf. A000005 (divisor function d(n))
Sequence in context: A066475 A106930 A106929 * A091490 A091075 A288409
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended and corrected by T. D. Noe, Nov 21 2010
STATUS
approved