cp's OEIS Frontend

A046831 Numbers k such that decimal expansion of k^2 contains k as a substring and k does not end in 0.

%I A046831 #26 Apr 04 2023 15:25:34
%S A046831 1,5,6,25,76,376,625,3792,9376,14651,90625,109376,495475,505025,
%T A046831 890625,971582,1713526,2890625,4115964,5133355,6933808,7109376,
%U A046831 10050125,12890625,48588526,50050025,66952741,87109376,88027284,88819024
%N A046831 Numbers k such that decimal expansion of k^2 contains k as a substring and k does not end in 0.
%C A046831 Subsequence of A018834. - _Chai Wah Wu_, Apr 04 2023
%H A046831 Giovanni Resta, <a href="/A046831/b046831.txt">Table of n, a(n) for n = 1..64</a>
%t A046831 Reap[For[n = 1, n < 10^8, n++, If[Mod[n, 10] != 0, If[StringPosition[ToString[n^2], ToString[n]] != {}, Print[n]; Sow[n]]]]][[2, 1]] (* _Jean-François Alcover_, Apr 04 2013 *)
%o A046831 (Haskell)
%o A046831 a046831 n = a046831_list !! (n-1)
%o A046831 a046831_list = filter ((> 0) . (`mod` 10)) a018834_list
%o A046831 -- _Reinhard Zumkeller_, Jul 27 2011
%o A046831 (Python)
%o A046831 from itertools import count, islice
%o A046831 def A046831_gen(startvalue=0): # generator of terms >= startvalue
%o A046831     return filter(lambda n:n%10 and str(n) in str(n**2), count(max(startvalue,0)))
%o A046831 A046831_list = list(islice(A046831_gen(),20)) # _Chai Wah Wu_, Apr 04 2023
%Y A046831 Cf. A018834, A003226, A008851.
%K A046831 nonn,base
%O A046831 1,2
%A A046831 _David W. Wilson_