cp's OEIS Frontend

A281822 Least number k such that (k+n)^2 contains k as a substring.

%I A281822 #16 Feb 28 2017 03:07:33
%S A281822 1,8,6,1,4,9,62,6,1,1,1,1,1,1,2,2,2,4,1,5,1,2,9,2,4,2,92,9,1,5,1,1,1,
%T A281822 1,1,1,1,1,1,1,1,1,1,1,2,1,2,2,1,2,1,2,2,1,3,1,3,3,1,2,1,4,4,2,4,4,2,
%U A281822 4,1,5,1,1,5,2,4,2,4,2,1,5,1,6,5,2,4,8,6
%N A281822 Least number k such that (k+n)^2 contains k as a substring.
%H A281822 Paolo P. Lava, <a href="/A281822/b281822.txt">Table of n, a(n) for n = 0..10000</a>
%e A281822 a(1) = 8 because (8 + 1)^2 = 9^2 = 81 contains 8 as a substring and it is the least number with this property.
%p A281822 with(numtheory): P:= proc(q) local a,b,d,j,k,n,ok;
%p A281822 for n from 0 to q do for k from 1 to q do a:=ilog10(k)+1; b:=(n+k)^2; d:=ilog10((k+n)^2)-ilog10(k)+1;
%p A281822 ok:=0; for j from 1 to d do if k=(b mod 10^a) then ok:=1; break; else b:=trunc(b/10); fi; od;
%p A281822 if ok=1 then print(k); break; fi; od; od; end: P(10^6);
%Y A281822 Cf.  A018834, A281823.
%K A281822 nonn,base,easy
%O A281822 0,2
%A A281822 _Paolo P. Lava_, Jan 31 2017
%E A281822 Typo in definition corrected by _Harvey P. Dale_, Feb 27 2017.
%E A281822 Entries, Maple code and b-file corrected at the suggestion of _Harvey P. Dale_, Feb 28 2017.