cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A067712 Numbers n such that sum of exponents in prime factorization of n is > log(n).

Original entry on oeis.org

2, 4, 6, 8, 12, 16, 18, 20, 24, 32, 36, 40, 48, 54, 64, 72, 80, 96, 108, 112, 120, 128, 144, 160, 192, 216, 224, 240, 256, 288, 320, 324, 336, 352, 360, 384, 400, 432, 448, 480, 512, 576, 640, 648, 672, 704, 720, 768, 800, 832, 864, 896, 960, 972, 1008, 1024, 1056
Offset: 1

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Author

Leroy Quet, Feb 05 2002

Keywords

Examples

			a(1) = 2 because 2 has 1 prime factor, viz., 2 and log(2) ~= 0.693 and 1 > 0.693.
4 is included because sum of exponents in prime factorization of 4 is 2, which is > log(4).
		

References

  • Conway, John H. and Guy, Richard K., The Book of Numbers, Copernicus, 1996, pp. 132-133.
  • Ore, Oystein, Number Theory and Its History, McGraw-Hill, 1948, (also reprinted 1988), pp. 50-52.

Crossrefs

Programs

  • Mathematica
    Select[Range[2,1100],Total[FactorInteger[#][[All,2]]]>Log[#]&] (* Harvey P. Dale, Feb 04 2019 *)

Formula

OMEGA(n) > log(n), where OMEGA is the total number of prime factors.

Extensions

More terms from Walter Nissen, Mar 10 2003