A256405 a(n) = smallest missing number after seeing A166133(n).

2, 3, 3, 5, 5, 5, 5, 9, 9, 9, 9, 13, 13, 13, 13, 17, 17, 17, 17, 17, 22, 22, 22, 25, 25, 25, 25, 25, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67

Offset: 1

Author

N. J. A. Sloane, Apr 01 2015

Keywords

• nonn

Comments

The distinct terms are listed in A256408. See also A256409.

See the "blog" file in A166133 for discussion.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• John Mason, Table of n, a(n) for n = 1..722392 [10 megabytes]
• John Mason, Table of n, a(n) for n = 1..2000000 [31 megabytes]
• John Mason, Ten million terms (zipped file)

Crossrefs

Cf. A166133, A027750, A005563, A256408, A256409.

Programs

Haskell

import Data.List (delete); import Data.List.Ordered (isect)
a256405 n = a256405_list !! (n-1)
a256405_list = 2 : 3 : f (3:[5..]) 4 where
   f zs@(z:_) x = z : f (delete y zs) y where
                  y = head $ isect (a027750_row' (x ^ 2 - 1)) zs
-- Reinhard Zumkeller, Apr 01 2015