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A256406 Numbers n such that for some m, A166133(m)=n, A166133(m+1)=n^2-1, in order of increasing m. 3
3, 198, 270, 570, 522, 600, 822, 882, 1062, 2130, 1950, 2592, 2268, 2310, 3168, 2970, 5502, 6702, 5022, 7350, 10038, 10428, 10500, 9438, 14562, 14010, 15288, 17028, 18060, 19698, 17958, 19890, 18522, 20772, 29670, 20550, 22158, 16650 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
In other words, the next term in A166133 after n is as large as it can be. Terms are listed in order of appearance in A166133.
With the exception of the initial 3, the terms appear to be a (permuted) subset of A014574; i.e. the divisors of a(n)^2-1 are 1, a(n)-1, a(n)+1, and a(n)^2-1. - Hans Havermann, Apr 03 2015
See the "blog" file in A166133 for discussion.
LINKS
Hans Havermann and John Mason, Table of n, a(n) for n = 1..6575 [Terms 1 through 480 were computed by Hans Havermann; terms 481 through 6575 by John Mason, Apr 05 2015]
PROG
(Haskell)
a256406 n = a256406_list !! (n-1)
a256406_list = f a166133_list where
f (u:vs'@(v:ws)) | u > v || v /= u ^ 2 - 1 = f vs'
| otherwise = u : f ws
-- Reinhard Zumkeller, Apr 01 2015
CROSSREFS
Cf. A014574, A166133, A256407 (sorted version).
Sequence in context: A209120 A336250 A256407 * A157565 A157598 A023310
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 01 2015, based on a comment of Franklin T. Adams-Watters in A166133.
STATUS
approved

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Last modified March 28 10:55 EDT 2024. Contains 371241 sequences. (Running on oeis4.)