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A241241 If x is in the sequence then so are x^2 and x(x+1)/2. 2
0, 1, 2, 3, 4, 6, 9, 10, 16, 21, 36, 45, 55, 81, 100, 136, 231, 256, 441, 666, 1035, 1296, 1540, 2025, 3025, 3321, 5050, 6561, 9316, 10000, 18496, 26796, 32896, 53361, 65536, 97461, 194481, 222111, 443556, 536130, 840456, 1071225, 1186570, 1679616, 2051325 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

MATHEMATICA

Nest[Flatten[{#, #^2, (#(#+1))/2}]&, {0, 1, 2}, 5]//Union (* Harvey P. Dale, Aug 12 2016 *)

PROG

(Haskell)

import Data.Set (singleton, deleteFindMin, insert)

a241241 n = a241241_list !! (n-1)

a241241_list = 0 : 1 : f (singleton 2) where

   f s = m : f (insert (a000290 m) $ insert (a000217 m) s')

         where (m, s') = deleteFindMin s

CROSSREFS

Cf. A000290, A000217.

Subsequence of A005214; some subsequences: A001146, A007501, A011764, A176594, A173501, A050909.

Sequence in context: A046097 A239580 A175515 * A260343 A215818 A132600

Adjacent sequences:  A241238 A241239 A241240 * A241242 A241243 A241244

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Apr 17 2014

EXTENSIONS

Initial 0 and 1 prepended by Jon Perry, Apr 17 2014

STATUS

approved

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Last modified November 16 22:05 EST 2019. Contains 329208 sequences. (Running on oeis4.)