A332797 Numbers whose smallest prime factor is 23.

23, 529, 667, 713, 851, 943, 989, 1081, 1219, 1357, 1403, 1541, 1633, 1679, 1817, 1909, 2047, 2231, 2323, 2369, 2461, 2507, 2599, 2921, 3013, 3151, 3197, 3427, 3473, 3611, 3749, 3841, 3979, 4117, 4163, 4393, 4439, 4531, 4577, 4853, 5129, 5221, 5267, 5359, 5497

Offset

1,1

Comments

The asymptotic density of this sequence is 55296/7436429. - Amiram Eldar, Dec 06 2020

References

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

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = 23*A166063(n).

Example

a(2) = 23*23, a(3) = 23*29.

Mathematica

23 * Select[Range[240], CoprimeQ[#, 9699690] &] (* Amiram Eldar, Feb 24 2020 *)

Prog

(Rexx)
P = 23         ;  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

Crossrefs

Cf. A084967 (5), A084968 (7), A084969 (11), A084970 (13), A332799 (17), A332798 (19), A166063 (23-rough numbers).

Sequence in context: A118338 A171328 A097778 * A057193 A014960 A207230

Adjacent sequences: A332794 A332795 A332796 * A332798 A332799 A332800

Keyword

nonn,easy

Author

Frank Ellermann, Feb 24 2020

Status

approved