OFFSET
0,2
COMMENTS
Binary representations:
a(0) 1
a(1) 101
a(2) 1010011
a(3) 1010011000111
a(4) 101001100011100001111
a(5) 1010011000111000011110000011111
a(6) 1010011000111000011110000011111000000111111
a(7) 101001100011100001111000001111100000011111100000001111111
a(8) 1010011000111000011110000011111000000111111000000011111110000000011111111
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..57
FORMULA
a(0)=1, a(n) = a(n-1)*4^n + 2^n - 1.
MATHEMATICA
nxt[{n_, a_}]:={n+1, FromDigits[Join[IntegerDigits[a], PadRight[{}, n, 0], PadRight[ {}, n, 1]]]}; FromDigits[IntegerDigits[#], 2]&/@NestList[nxt, {1, 1}, 12][[All, 2]] (* Harvey P. Dale, Apr 30 2019 *)
PROG
(Python)
a = 1
for n in range(1, 13):
#print 'a('+str(n-1)+')', bin(a)[2:], a
print a,
a = a*(4**n) + 2**n - 1
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Alex Ratushnyak, Aug 05 2012
STATUS
approved