login
A245425
Number of nonnegative integers with the property that their base 9/4 expansion (see A024652) has n digits.
0
9, 18, 36, 81, 180, 405, 918, 2061, 4635, 10431, 23472, 52812, 118827, 267363, 601560, 1353510, 3045402, 6852150, 15417342, 34689015, 78050286, 175613148, 395129583, 889041555, 2000343501, 4500772875, 10126738971, 22785162687, 51266616048, 115349886108
OFFSET
1,1
EXAMPLE
The numbers 9-26 are represented by 40, 41, 42, 43, 44, 45, 46, 47, 48, 80, 81, 82, 83, 84, 85, 86, 87, 88 respectively in base 9/4. Since these are the only two digit integers we have a(2) = 18.
PROG
(Sage)
A=[1]
for i in [1..100]:
A.append(ceil(((9-4)/4)*sum(A)))
[9*x for x in A]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Tom Edgar, Jul 21 2014
STATUS
approved