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%I #15 Aug 16 2014 10:14:37
%S 1,419,1641925,36164192549,643616419254981,100643616419254981121,
%T 144100643616419254981121169,196144100643616419254981121169225,
%U 256196144100643616419254981121169225289
%N Let s(n) be the sequence of squares (A000290). Then this sequence is given by s(1), s(2)s(1)s(3), s(4)s(2)s(1)s(3)s(5), ...
%C a(n) is the concatenation of squares about 1 with even squares on the left and the odd squares on the right.
%H Vincenzo Librandi, <a href="/A061118/b061118.txt">Table of n, a(n) for n = 1..50</a>
%H Felice Russo, <a href="http://www.gallup.unm.edu/~smarandache/Felice-Russo-book1.pdf">A Set of New Smarandache Functions, Sequences and Conjectures in Number Theory.</a>, Lupton, AZ: American Research Press, 2000.
%e a(3) = 1641925, concatenation of 16, 4, 1, 9 and 25.
%p for n from 1 to 15 do for k from 2*(n-1) to 2 by -2 do printf(`%d`, k^2) od: for k from 1 to 2*n-1 by 2 do printf(`%d`, k^2) od: printf(`,`): od:
%t Table[Module[{sqs=Range[n]^2},FromDigits[Flatten[IntegerDigits/@ Join[ Reverse[ Select[ sqs,EvenQ]],Select[sqs,OddQ]]]]],{n,1,21,2}] (* _Harvey P. Dale_, Aug 13 2014 *)
%K nonn,base,less
%O 1,2
%A _Amarnath Murthy_, Apr 21 2001
%E More terms from _James A. Sellers_, Apr 23 2001