cp's OEIS Frontend

A162917 Numbers n which are not in A161983.

%I A162917 #25 Dec 11 2019 07:18:04
%S A162917 1,2,6,7,8,9,15,16,17,18,19,20,28,29,30,31,32,33,34,35,45,46,47,48,49,
%T A162917 50,51,52,53,54,66,67,68,69,70,71,72,73,74,75,76,77,91,92,93,94,95,96,
%U A162917 97,98,99,100,101,102,103,104,120,121,122,123,124,125,126,127,128
%N A162917 Numbers n which are not in A161983.
%C A162917 They have a block structure: A000384(n) is followed by the next n integers.
%C A162917 Numbers k with the property that the largest Dyck path of the symmetric representation of sigma(k) has a central peak. (Cf. A237593.) - _Omar E. Pol_, Aug 28 2018
%C A162917 Union of nonzero terms of A000384 and A317303. - _Omar E. Pol_, Aug 29 2018
%F A162917 A000027 \ A161983.
%e A162917 From _Omar E. Pol_, Aug 28 2018: (Start)
%e A162917 Also, written as an irregular triangle in which the row lengths are the positive even numbers, the sequence begins:
%e A162917    1,  2;
%e A162917    6,  7,  8,  9;
%e A162917   15, 16, 17, 18, 19, 20;
%e A162917   28, 29, 30, 31, 32, 33, 34, 35;
%e A162917   45, 46, 47, 48, 49, 50, 51, 52, 53,  54;
%e A162917   66, 67, 68, 69, 70, 71, 72, 73, 74,  75,  76,  77;
%e A162917   91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104;
%e A162917 ...
%e A162917 Row sums give A035328, n >= 1.
%e A162917 Column 1 gives A000384, n >= 1.
%e A162917 Column 2 gives A130883, n >= 1.
%e A162917 Right border gives the positive terms of A014107, also the odd-indexed terms of A000096.
%e A162917 (End)
%Y A162917 Complement of A161983.
%Y A162917 Cf. A000096, A000384, A014107, A035328, A130883, A237593, A317303.
%K A162917 nonn,tabf
%O A162917 1,2
%A A162917 _Juri-Stepan Gerasimov_, Jul 17 2009
%E A162917 119 removed by _R. J. Mathar_, Jul 19 2009