A251549 a(n) = smallest odd number not in {A098550(1), A098550(2), ..., A098550(n)}.

3, 3, 5, 5, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, 11, 11, 11, 11, 11, 11, 11, 13, 17, 17, 17, 17, 17, 17, 17, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 23, 23, 23, 23, 23, 23, 23, 23, 29, 29, 29, 29, 29, 29, 29, 29, 29

Offset: 1

Author

N. J. A. Sloane, Dec 18 2014

Keywords

• nonn

Comments

A251416(n) = Min{A251546(n), a(n)}. - Reinhard Zumkeller, Dec 19 2014

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A098550, A247253, A251416, A251417, A251546-A251552.

Programs

Haskell

import Data.List ((\\))
a251549 n = head $ [1, 3 ..] \\ filter odd (take n a098550_list)
-- Reinhard Zumkeller, Dec 19 2014

Mathematica

terms = 100;
f[lst_List] := Block[{k=4}, While[GCD[lst[[-2]], k] == 1 || GCD[lst[[-1]], k] > 1 || MemberQ[lst, k], k++]; Append[lst, k]];
A098550 = Nest[f, {1, 2, 3}, terms-3];
a[1] = 3;
a[n_] := a[n] = For[k = a[n-1], True, k = k+2, If[FreeQ[A098550[[1 ;; n]], k], Return[k]]];
Array[a, terms] (* Jean-François Alcover, Aug 02 2018, after Robert G. Wilson v *)