

A176525


FermiDirac semiprimes: products of two distinct terms of A050376


3



6, 8, 10, 12, 14, 15, 18, 20, 21, 22, 26, 27, 28, 32, 33, 34, 35, 36, 38, 39, 44, 45, 46, 48, 50, 51, 52, 55, 57, 58, 62, 63, 64, 65, 68, 69, 74, 75, 76, 77, 80, 82, 85, 86, 87, 91, 92, 93, 94, 95, 98, 99, 100, 106, 111, 112, 115, 116, 117, 118, 119, 122
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OFFSET

1,1


COMMENTS

The sequence essentially differs from A000379 beginning with a(108)=212 (not 210). All squarefree terms of A001358 are in the sequence. The sequence essentially differs also from A064176 which contains products of even distinct terms of A050376


REFERENCES

S. Litsyn and V. S. Shevelev, On factorization of integers with restrictions on the exponent, INTEGERS: Electronic Journal of Combinatorial Number Theory, 7 (2007), #A33, 136.
V. S. Shevelev, Multiplicative functions in the FermiDirac arithmetic, Izvestia Vuzov of the NorthCaucasus region, Nature sciences 4 (1996), 2843 [Russian].


LINKS

Table of n, a(n) for n=1..62.


FORMULA

If a(n)=u*v, u<v, u,v are distinct terms of A050376 "FermiDirac primes", then A064380(a(n))=a(n)uv+1+Sum{i>=1}(1)^(i1)*floor(v/u^i).


CROSSREFS

Cf. A001358 A050376 A000379 A176472 A176509 A064380 A050292
Cf. A064176. [From R. J. Mathar, Apr 29 2010]
Sequence in context: A131181 A064176 A000379 * A065985 A233421 A060652
Adjacent sequences: A176522 A176523 A176524 * A176526 A176527 A176528


KEYWORD

nonn


AUTHOR

Vladimir Shevelev, Apr 19 2010, Apr 20 2010


STATUS

approved



