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A254334
Powers of 3 in base 60, concatenating the decimal values of the sexagesimal digits.
5
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
0,2
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".
LINKS
FORMULA
a(n) = A055643(A000244(n)). - Michel Marcus, Mar 02 2015
EXAMPLE
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.
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 *)
PROG
(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
CROSSREFS
Cf. A000244 (Powers of 3), A055643 (Babylonian numbers).
Cf. Sexagesimal representations: A250073 (Powers of 2), A254335 (Powers of 5), A254336 (Powers of 10).
Sequence in context: A323927 A146151 A306681 * A375093 A028855 A299597
KEYWORD
nonn,base
AUTHOR
Michael De Vlieger, Jan 28 2015
STATUS
approved