login
A214936
a(0) = 1, a(n) = a(n - 1) * (length of binary representation of n).
0
1, 1, 2, 4, 12, 36, 108, 324, 1296, 5184, 20736, 82944, 331776, 1327104, 5308416, 21233664, 106168320, 530841600, 2654208000, 13271040000, 66355200000, 331776000000, 1658880000000, 8294400000000, 41472000000000, 207360000000000, 1036800000000000, 5184000000000000
OFFSET
0,3
FORMULA
a(0) = 1, for n > 0: a(n) = a(n - 1) * (Length of binary representation of n) = a(n - 1) * A070939(n).
EXAMPLE
a(4) = 12 because a(3) = 4 and 4 in binary is 100 (3 bits), and thus 4 * 3 = 12.
MATHEMATICA
nxt[{n_, a_}]:={n+1, a*IntegerLength[n+1, 2]}; Transpose[NestList[nxt, {0, 1}, 30]][[2]] (* Harvey P. Dale, Oct 11 2015 *)
PROG
(Python)
t = 1
for n in range(1, 33):
print t,
t *= len(bin(n))-2
CROSSREFS
Cf. A070939.
Cf. A083652: a(0)=1, for n>0: a(n)=a(n-1)+A070939(n).
Sequence in context: A149840 A224540 A025579 * A010552 A149841 A149842
KEYWORD
nonn,base,easy
AUTHOR
Alex Ratushnyak, Jul 29 2012
STATUS
approved