cp's OEIS Frontend

A030623 Powers of 2 grouped in pairs of 2 digits (version 2).

%I A030623 #14 Mar 28 2020 19:21:16
%S A030623 12,48,16,32,64,12,82,56,51,21,2,42,4,84,9,68,19,21,63,84,32,76,86,55,
%T A030623 36,13,10,72,26,21,44,52,42,88,10,48,57,62,9,71,52,41,94,30,48,38,86,
%U A030623 8,16,77,72,16,33,55,44,32,67,10,88,64,13,42,17,72,82,68,43,54,56,53,68
%N A030623 Powers of 2 grouped in pairs of 2 digits (version 2).
%C A030623 When a 0 occurs as the most significant digit of the pair, it is simply ignored, e.g., "02" becomes just 2. The following pairs are unaffected. - _Alonso del Arte_, Mar 28 2020
%e A030623 The first few powers of 2 are 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192. The digits are 1, 2, 4, 8, 1, 6, 3, 2, 6, 4, 1, 2, 8, 2, 5, 6, 5, 1, 2, 1,0, 2, 4, 2, 0, 4, 8, 4, 0, 9, 6. Grouping them in pairs, we obtain 12, 48, 16, 32, 64, 12, 82, 56, 51, 21, 02, 42, 04, 84, 09, 68, etc.
%p A030623 sq:=[]: for n from 0 to 100 do s:=convert(2^n,base,10): l:=nops(s): sq:=[op(sq),seq(s[l-i],i=0..l-1)] od: seq(sq[2*i-1]*10+sq[2*i],i=1..100); # C. Ronaldo
%t A030623 FromDigits/@Partition[Flatten[IntegerDigits[2^Range[0, 63]]], 2] (* _Alonso del Arte_, Mar 28 2020 *)
%o A030623 (Scala) (List.fill(63)(2: BigInt)).scanLeft(1: BigInt)(_ * _).map(_.toString.toCharArray).flatten.sliding(2, 2).map(_.toArray).toList.map(new String(_)).map(Integer.parseInt(_)) // _Alonso del Arte_, Mar 28 2020
%Y A030623 Cf. A030622, A030624, A000079, A000455.
%K A030623 nonn,base,easy
%O A030623 1,1
%A A030623 Alexei Kozlowski (bros(AT)spf.minsk.by)
%E A030623 More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 03 2005