A086013 - OEIS

%I #16 Dec 15 2017 17:36:31

%S 0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,1,1,0,0,0,0,0,0,0,0,

%T 1,1,0,0,0,1,0,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,1,0,

%U 0,0,0,1,1,1,1,2,1,1,0,0,0,1,0,0,1,1,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0

%N Number of 5's in decimal expansion of n^2.

%H G. C. Greubel, <a href="/A086013/b086013.txt">Table of n, a(n) for n = 0..1000</a>

%t DigitCount[(Range[0,110])^2,10,5] (* _Harvey P. Dale_, Jul 26 2016 *)

%o (PARI) A086013(n)=#select(d->d==5,digits(n^2)) \\ _M. F. Hasler_, Feb 21 2016

%Y Cf. 0's A086008, 1's A086009, 2's A086010, 3's A086011, 4's A086012, 6's A086014, 7's A086015, 8's A086016, 9's A086017.

%Y Cf. A269245 for the n^3 analog.

%K base,nonn

%O 0,76

%A _Jason Earls_, Jul 07 2003