OFFSET
1,1
COMMENTS
Binary expansion is 1001, 110011, 11100111, 1111001111, ...
Last digit of the decimal representation follows the pattern 9, 1, 1, 5, 9, 1, 1, 5, 9, ...
LINKS
Index entries for linear recurrences with constant coefficients, signature (7,-14,8).
FORMULA
a(n) = 2^(2*n + 2) - 2^(n + 1) - 2^n - 1.
a(n) = 7*a(n-1)-14*a(n-2)+8*a(n-3). G.f.: 3*x*(4*x-3) / ((x-1)*(2*x-1)*(4*x-1)). - Colin Barker, May 31 2013
MATHEMATICA
Table[2^(2n + 2) - 2^(n + 1) - 2^n - 1, {n, 25}] (* Alonso del Arte, Dec 08 2012 *)
LinearRecurrence[{7, -14, 8}, {9, 51, 231}, 30] (* Harvey P. Dale, Jan 24 2019 *)
PROG
(Python)
for n in range(1, 77):
print (2**(2*n+2)-2**n-2**(n+1)-1),
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Alex Ratushnyak, Dec 08 2012
STATUS
approved