cp's OEIS Frontend

A028319 Distinct odd elements in the 5-Pascal triangle A028313.

%I A028319 #13 Jul 02 2025 16:01:56
%S A028319 1,5,7,19,9,27,65,11,101,57,147,231,13,69,273,15,355,855,111,451,2277,
%T A028319 17,127,1661,3487,5379,689,2223,11583,833,7371,20449,181,995,3745,
%U A028319 10283,21385,34463,43615,21,201,1377,23,1599,7293,267,1843,31977,25
%N A028319 Distinct odd elements in the 5-Pascal triangle A028313.
%H A028319 G. C. Greubel, <a href="/A028319/b028319.txt">Table of n, a(n) for n = 0..1000</a>
%t A028319 DeleteDuplicates[Table[If[n<2, 1, Binomial[n,k] +3*Binomial[n-2,k-1]], {n,0,30}, {k,0,n}]//Flatten]//Select[OddQ] (* _G. C. Greubel_, Jul 13 2024 *)
%o A028319 (SageMath)
%o A028319 def A028323(n, k): return 1 if n<2 else binomial(n, k) + 3*binomial(n-2, k-1)
%o A028319 b=flatten([[A028323(n, k) for k in range(n+1)] for n in range(31)])
%o A028319 def a(seq): # order preserving
%o A028319     nd = [] # no duplicates
%o A028319     [nd.append(i) for i in seq if not nd.count(i) and i%2==1]
%o A028319     return nd
%o A028319 a(b) # A028319 # _G. C. Greubel_, Jul 13 2024
%Y A028319 Cf. A028313, A028314, A028315, A028316, A028317, A028318, A028320.
%Y A028319 Cf. A028321, A028322, A028323, A028324, A028325, A051472.
%K A028319 nonn
%O A028319 0,2
%A A028319 _Mohammad K. Azarian_
%E A028319 More terms from _James Sellers_, Dec 08 1999