cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A245425 Number of nonnegative integers with the property that their base 9/4 expansion (see A024652) has n digits.

Original entry on oeis.org

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

Views

Author

Tom Edgar, Jul 21 2014

Keywords

Examples

			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.
		

Crossrefs

Programs

  • Sage
    A=[1]
    for i in [1..100]:
        A.append(ceil(((9-4)/4)*sum(A)))
    [9*x for x in A]