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.

A254334 Powers of 3 in base 60, concatenating the decimal values of the sexagesimal digits.

Original entry on oeis.org

1, 3, 9, 27, 121, 403, 1209, 3627, 14921, 52803, 162409, 491227, 2273721, 7225203, 22083609, 106254827, 319172521, 957521603, 2953364809, 12940502427, 42902311321, 132707334003, 402122410009, 2010408030027, 6031224090121, 18093712270403, 54285137211209
Offset: 0

Views

Author

Michael De Vlieger, Jan 28 2015

Keywords

Comments

Each sexagesimal digit appears as a pair of decimal digits as on a digital clock. Any leading zeros are truncated. Thus decimal 81 appears as "121" and not "0121".

Examples

			a(6) = 1209, since 3^6 = 729 = 12 * 60^1 + 9, thus 12:09 in clock-like notation, which becomes 1209 when restricted to numeric characters.
		

Crossrefs

Cf. A000244 (Powers of 3), A055643 (Babylonian numbers).
Cf. Sexagesimal representations: A250073 (Powers of 2), A254335 (Powers of 5), A254336 (Powers of 10).

Programs

  • Mathematica
    f[n_] := FromDigits@ StringJoin[If[# < 10, StringJoin["0", ToString[#]], ToString[#]] & /@ IntegerDigits[3^n, 60]]; Table[f@ i, {i, 0, 26}] (* Michael De Vlieger, Jan 28 2015 *)
  • PARI
    a(n) = subst(Pol(digits(3^n, 60)), x, 100); \\ Michel Marcus, Feb 22 2015
    
  • Python
    def digits(n,b=10): # list of digits of n in base b
        x, y = n, []
        while x >= b:
            x, r = divmod(x,b)
            y.append(r)
        y.append(x)
        return list(reversed(y))
    A254334_list = [int(''.join([format(x,'02d') for x in digits(3**i, 60)])) for i in range(10**2)]
    # Chai Wah Wu, Mar 14 2015

Formula

a(n) = A055643(A000244(n)). - Michel Marcus, Mar 02 2015