A050941 Numbers that are not the sum of consecutive triangular numbers.

2, 5, 7, 8, 11, 12, 13, 14, 17, 18, 22, 23, 24, 26, 27, 29, 30, 32, 33, 37, 38, 39, 40, 41, 42, 43, 44, 47, 48, 50, 51, 53, 54, 57, 58, 59, 60, 61, 62, 63, 65, 67, 68, 69, 70, 71, 72, 73, 75, 76, 77, 79, 82, 86, 87, 88, 89, 90, 92, 93, 94, 95, 96, 97

Offset: 1

Author

N. J. A. Sloane, Jan 02 2000

Keywords

• nonn

Comments

Numbers that are not the difference of two tetrahedral numbers. - Franklin T. Adams-Watters, Dec 16 2015

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Complement of A034706.

Programs

Haskell

import Data.List.Ordered (minus)
a050941 n = a050941_list !! (n-1)
a050941_list = minus [0..] a034706_list
-- Reinhard Zumkeller, May 12 2015

Mathematica

lim = 20; Take[#, Floor[Length[#]/lim]] &@ Complement[Range@ Max@ #, #] &@ Union[Subtract @@@ Map[Sort[#, Greater] &, Permutations[Table[Binomial[n + 2, 3], {n, 0, lim}], {2}]]] (* Michael De Vlieger, Dec 17 2015, in part after Zerinvary Lajos at A000292 *)