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a(n+1) is next smallest square not divisible by 10 beginning with a(n), initial term is 7.
5

%I #17 Nov 19 2014 21:42:57

%S 7,729,729316,7293164743396,72931647433968832639882896,

%T 72931647433968832639882896319584064899663299793041401

%N a(n+1) is next smallest square not divisible by 10 beginning with a(n), initial term is 7.

%H Hiroaki Yamanouchi, <a href="/A249897/b249897.txt">Table of n, a(n) for n = 1..10</a>

%o (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 a(7)

%o (Python)

%o def f(x):

%o ..print(x, end=', ')

%o ..n = x

%o ..s = 1

%o ..while s < 10**7:

%o ....if s % 10:

%o ......S = str(s**2)

%o ......if S.startswith(str(n)):

%o ........print(s**2, end=', ')

%o ........n = s**2

%o ....s += 1

%o f(7)

%Y Cf. A048559, A048561.

%K nonn,base

%O 1,1

%A _Derek Orr_, Nov 08 2014

%E a(5)-a(6) corrected by _Hiroaki Yamanouchi_, Nov 17 2014