OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
MATHEMATICA
DeleteDuplicates[Table[If[n<2, 1, Binomial[n, k] +3*Binomial[n-2, k-1]], {n, 0, 30}, {k, 0, n}]//Flatten] (* G. C. Greubel, Jul 03 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)]
return nd
a(b) # A028318 # G. C. Greubel, Jul 03 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from James A. Sellers, Dec 08 1999
STATUS
approved