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.

A332799 Numbers whose smallest prime factor is 17.

Original entry on oeis.org

17, 289, 323, 391, 493, 527, 629, 697, 731, 799, 901, 1003, 1037, 1139, 1207, 1241, 1343, 1411, 1513, 1649, 1717, 1751, 1819, 1853, 1921, 2159, 2227, 2329, 2363, 2533, 2567, 2669, 2771, 2839, 2941, 3043, 3077, 3247, 3281, 3349, 3383, 3587, 3791, 3859, 3893
Offset: 1

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Author

Frank Ellermann, Feb 24 2020

Keywords

Comments

The asymptotic density of this sequence is 192/17017. - Amiram Eldar, Dec 06 2020

Examples

			a(2) = 17*17, a(3) = 17*19.
		

References

  • Emmanuel Desurvire, Classical and Quantum Information Theory: An Introduction for the Telecom Scientist, Cambridge University Press, 2009, table 20.5 p. 421.

Crossrefs

Cf. A084967 (5), A084968 (7), A084969 (11), A084970 (13), A332798 (19), A332797 (23), A008366 (17-rough numbers).

Programs

  • Mathematica
    17 * Select[Range[230], CoprimeQ[#, 30030] &] (* Amiram Eldar, Feb 24 2020 *)
  • Rexx
    P = 17         ;  S = P
    do N = P by 2 while length( S ) < 255
       do I = 1 until P = X
          X = PRIME( I )
          if P = X       then  leave I
          if N // X = 0  then  iterate N
       end I
       S = S || ',' P*N
    end N
    say S          ;  return S

Formula

a(n) = 17*A008366(n).