login
Numbers k such that k has sqrt(k) as its middle digits.
1

%I #9 Jul 17 2021 04:30:17

%S 1,2500,3600,62500,14379264,57760000,141376000000,245495475625,

%T 390625000000,943971582724,4482669527413081,8790937600000000,

%U 31561776563446336,10235319926865509025

%N Numbers k such that k has sqrt(k) as its middle digits.

%F a(n) = A062118(n)^2.

%t Do[ If[ StringPosition[ ToString[n^2], ToString[n]] [[1, 1]] == (Ceiling[ Log[10, n^2] ] - Ceiling[ Log[10, n] ])/2 + 1, Print[n^2] ], {n, 1, 10^9} ]

%Y Cf. A062118.

%K nonn,base

%O 1,2

%A Brian Wallace (wallacebrianedward(AT)yahoo.co.uk), Jun 28 2001