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A249894 a(n+1) is next smallest square not divisible by 10 beginning with a(n), initial term is 3.

%I A249894 #15 May 22 2025 10:21:41
%S A249894 3,36,361,361201,36120142809,3612014280924268428225,
%T A249894 361201428092426842822525044572369542546150009
%N A249894 a(n+1) is next smallest square not divisible by 10 beginning with a(n), initial term is 3.
%H A249894 Hiroaki Yamanouchi, <a href="/A249894/b249894.txt">Table of n, a(n) for n = 1..10</a>
%o A249894 (PARI) a(n)=k=n; s=1; while(s<5*10^7, if(s%10, if(s^2\(10^(#Str(s^2)-#Str(k)))==k, print1(s^2, ", "); k=s^2)); s++)
%o A249894 a(3)
%o A249894 (Python)
%o A249894 def f(x):
%o A249894   print(x, end=', ')
%o A249894   n = x
%o A249894   s = 1
%o A249894   while s < 10**7:
%o A249894     if s % 10:
%o A249894       S = str(s**2)
%o A249894       if S.startswith(str(n)):
%o A249894         print(s**2, end=', ')
%o A249894         n = s**2
%o A249894     s += 1
%o A249894 f(3)
%Y A249894 Cf. A048559, A048561.
%K A249894 nonn,base
%O A249894 1,1
%A A249894 _Derek Orr_, Nov 08 2014
%E A249894 a(7) corrected by _Hiroaki Yamanouchi_, Nov 17 2014