A255617 a(n) is the smallest even term in A098550 less than 2*prime(n) but occurring after 2*prime(n); a(n)=0 if no such term exists.

0, 0, 0, 6, 18, 18, 30, 0, 0, 54, 54, 70, 78, 78, 90, 102, 110, 120, 0, 140, 144, 150, 0, 0, 0, 198, 200, 0, 216, 0, 252, 252, 270, 270, 0, 0, 310, 0, 0, 340, 348, 360, 374, 0, 0, 0, 402, 438, 440, 440, 450, 0, 0, 486, 486, 518, 528, 540, 546, 546, 0, 572, 0

Offset: 1

Author

Vladimir Shevelev, Feb 28 2015

Keywords

• nonn

Comments

Conjecture: for n>=5, positive a(n) > prime(n). Together with the known conjecture that, for n>=26, 2*prime(n) is the first multiple of prime(n) appearing in A098550, this conjecture would easily implies that the primes in A098550 occur in the natural order.

(Indeed, if 101<=P

Links

• Peter J. C. Moses, Table of n, a(n) for n = 1..1000
• 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.

Crossrefs

Cf. A098550, A255615.

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