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

1,1

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

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 *)

Prog

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

Crossrefs

Complement of A034706.

Sequence in context: A214518 A331866 A242401 * A299232 A153083 A140592

Adjacent sequences: A050938 A050939 A050940 * A050942 A050943 A050944

Keyword

nonn

Author

N. J. A. Sloane, Jan 02 2000

Status

approved