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A028319
Distinct odd elements in the 5-Pascal triangle A028313.
5
1, 5, 7, 19, 9, 27, 65, 11, 101, 57, 147, 231, 13, 69, 273, 15, 355, 855, 111, 451, 2277, 17, 127, 1661, 3487, 5379, 689, 2223, 11583, 833, 7371, 20449, 181, 995, 3745, 10283, 21385, 34463, 43615, 21, 201, 1377, 23, 1599, 7293, 267, 1843, 31977, 25
OFFSET
0,2
LINKS
MATHEMATICA
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 *)
PROG
(SageMath)
def A028323(n, k): return 1 if n<2 else binomial(n, k) + 3*binomial(n-2, k-1)
b=flatten([[A028323(n, k) for k in range(n+1)] for n in range(31)])
def a(seq): # order preserving
nd = [] # no duplicates
[nd.append(i) for i in seq if not nd.count(i) and i%2==1]
return nd
a(b) # A028319 # G. C. Greubel, Jul 13 2024
KEYWORD
nonn
EXTENSIONS
More terms from James A. Sellers, Dec 08 1999
STATUS
approved