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Powers of 2 written in base 60, concatenating the decimal values of the sexagesimal digits.
6

%I #14 Feb 01 2015 19:16:35

%S 1,2,4,8,16,32,104,208,416,832,1704,3408,10816,21632,43304,90608,

%T 181216,362432,1124904,2253808,4511616,9423232,19250504,38501008,

%U 117402016,235204032,510412104,1021224208,2042452416,4125304832,12251013704,24542031408,53124062816

%N Powers of 2 written in base 60, concatenating the decimal values of the sexagesimal digits.

%C Each sexagesimal digit appears as a pair of decimal digits as on a digital clock. Any leading zeros are truncated. Thus decimal 64 appears as "104" and not "0104".

%e a(7) = 208, since 2^7 = 128 = 2 sixties plus 8, thus 2:08 in clock-like notation, which becomes 208 when restricted to the numeric characters.

%t a250073[n_Integer] :=

%t FromDigits@

%t StringJoin[

%t If[# < 10, StringJoin["0", ToString[#]], ToString[#]] & /@

%t IntegerDigits[2^n, 60]]; a250073 /@ Range[60] (* _Michael De Vlieger_, Nov 11 2014 *)

%o (PARI) a(n) = {d = digits(2^n, 60); s = ""; for (i=1, #d, if (d[i] < 10, s = concat(s, "0")); s = concat(s, Str(d[i]))); eval(s);} \\ _Michel Marcus_, Nov 12 2014

%Y Cf. A000079.

%K nonn,base

%O 0,2

%A _Michael De Vlieger_, Nov 11 2014