A084004 - OEIS

%I #10 Sep 22 2024 13:52:06

%S 64,7921,9604,164836,351649,996004,19758025,20647936,29757025,

%T 30846916,97990201,99960004,1203187969,1975180249,3086469136,

%U 4265657344,8143618564,9999600004,115644884356,131504868496,132231867769,140039859961,173879826121,339900660100,391600608400

%N Squares obtained as a concatenation of k and 10's complement of k.

%H Andrew Howroyd, <a href="/A084004/b084004.txt">Table of n, a(n) for n = 1..65</a>

%F a(n) = A084005(n)^2. - _Andrew Howroyd_, Sep 21 2024

%o (PARI) b(n)={my(k=logint(n,10)+1); (n+1)*10^k - n}

%o { for(k=1, 10^6, my(x=b(k)); if(issquare(x), print1(x, ", "))) } \\ _Andrew Howroyd_, Sep 22 2024

%Y Cf. A084005, A084006, A084007.

%K base,nonn,changed

%O 1,1

%A _Amarnath Murthy_, May 23 2003

%E More terms from _Ray Chandler_, May 31 2003

%E Offset changed and a(22) onwards from _Andrew Howroyd_, Sep 21 2024