OFFSET
0,2
REFERENCES
F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier-North Holland, 1978, p. 631.
FORMULA
a(n) = 2*Product_{i=1..4n-2} (2^i + 1).
MATHEMATICA
Join[{1}, Table[2*Product[2^i+1, {i, 4n-2}], {n, 6}]] (* Harvey P. Dale, May 08 2013 *)
Table[Product[2^i + 1, {i, 0, n/2 - 2}], {n, 8, 40, 8}] (* Nathan J. Russell, Mar 04 2016 *)
PROG
(Python)
for n in range(8, 50, 8):
product = 1
for i in range(n//2 - 1):
product *= 2**i + 1
print(product, end=", ")
# Nathan J. Russell, Mar 01 2016
CROSSREFS
KEYWORD
nonn,easy,nice
AUTHOR
EXTENSIONS
There is an error in Eq. (75) of F. J. MacWilliams and N. J. A. Sloane, the lower subscript should be 1 not 0.
Formula corrected by N. J. A. Sloane, May 07 2013 following a suggestion from Harvey P. Dale
STATUS
approved