A251558 -id:A251558 - cp's OEIS frontend

A251546 a(n) = smallest even number not in {A098550(1), A098550(2), ..., A098550(n)}.

2, 4, 4, 6, 6, 6, 6, 6, 6, 10, 10, 10, 10, 10, 10, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 24, 24, 30, 30, 30, 30, 30, 30, 38, 38, 40, 40, 40, 40, 40, 40, 40, 46, 46, 46, 46, 46, 46, 46, 46, 54, 54, 54

Offset: 1

N. J. A. Sloane, Dec 18 2014

nonn

A251416(n) = Min{a(n), A251549(n)}. - Reinhard Zumkeller, Dec 19 2014

Chai Wah Wu, Table of n, a(n) for n = 1..10000
David L. Applegate, Hans Havermann, Bob Selcoe, Vladimir Shevelev, N. J. A. Sloane, and Reinhard Zumkeller, The Yellowstone Permutation, arXiv preprint arXiv:1501.01669 [math.NT], 2015 and J. Int. Seq. 18 (2015) 15.6.7.

Cf. A098550, A247253, A251416, A251417, A251547, A251548, A251549, A251550, A251551, A251552.

A251557 a(n) = 2 more than the largest even number among {A098550(1), A098550(2), ..., A098550(n)}.

Original entry on oeis.org

2, 4, 4, 6, 6, 10, 10, 16, 16, 16, 16, 16, 16, 18, 18, 18, 18, 22, 22, 24, 24, 24, 24, 24, 28, 28, 30, 30, 34, 34, 34, 34, 34, 34, 36, 36, 38, 38, 38, 38, 40, 40, 40, 44, 44, 46, 46, 46, 46, 52, 52, 52, 52, 54, 54, 54, 54, 58, 58, 64, 64, 64, 64, 64, 66, 66, 70, 70, 70, 70, 70, 70, 70

Offset: 1

N. J. A. Sloane, Dec 23 2014

nonn

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
David L. Applegate, Hans Havermann, Bob Selcoe, Vladimir Shevelev, N. J. A. Sloane, and Reinhard Zumkeller, The Yellowstone Permutation, arXiv preprint arXiv:1501.01669 [math.NT], 2015 and J. Int. Seq. 18 (2015) 15.6.7.

Cf. A098550, A251546, A251558, A251559.

a251557 n = a251557_list !! (n-1)
a251557_list = map (+ 2) $ tail $ scanl maxEven 0 a098550_list
               where maxEven u v = if even v then max u v else u
-- Reinhard Zumkeller, Mar 10 2015

terms = 100;
f[lst_] := 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] = 2; a[n_] := Max[Select[A098550[[1 ;; n]], EvenQ]] + 2;
Array[a, terms] (* Jean-François Alcover, Aug 02 2018, after Robert G. Wilson v *)

A251559 a(n) = 2 more than the largest odd number among {A098550(1), A098550(2), ..., A098550(n)} which is neither a prime nor a term of A251542.

Original entry on oeis.org

9, 9, 9, 9, 15, 15, 21, 21, 21, 21, 21, 21, 39, 39, 39, 39, 39, 39, 39, 39, 45, 45, 45, 45, 45, 49, 49, 55, 55, 55, 55, 55, 55, 57, 57, 69, 69, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 93, 99, 99, 105, 105, 105, 105, 121

Offset: 1

N. J. A. Sloane, Dec 23 2014

nonn

David L. Applegate, Hans Havermann, Bob Selcoe, Vladimir Shevelev, N. J. A. Sloane, and Reinhard Zumkeller, The Yellowstone Permutation, arXiv preprint arXiv:1501.01669 [math.NT], 2015 and J. Int. Seq. 18 (2015) 15.6.7.

Cf. A098550, A251546, A251557, A251558.

cp's OEIS Frontend

A251546 a(n) = smallest even number not in {A098550(1), A098550(2), ..., A098550(n)}.

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A251557 a(n) = 2 more than the largest even number among {A098550(1), A098550(2), ..., A098550(n)}.

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A251559 a(n) = 2 more than the largest odd number among {A098550(1), A098550(2), ..., A098550(n)} which is neither a prime nor a term of A251542.

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