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%I #12 Dec 15 2017 17:36:31
%S 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,1,1,0,0,0,0,0,
%T 0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
%U 0,1,0,0,0,0,1,0,2,0,0,0,0,0,1,0,1,1,1,1,2,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
%N Number of 7's in decimal expansion of n^2.
%H G. C. Greubel, <a href="/A086015/b086015.txt">Table of n, a(n) for n = 0..1000</a>
%t DigitCount[(Range[0, 100])^2, 10, 7] (* _G. C. Greubel_, Dec 13 2016 *)
%o (PARI) A086015(n)=#select(d->d==7,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, 5's A086013, 6's A086014, 8's A086016, 9's A086017.
%Y Cf. A269247 for the n^3 analog.
%K base,nonn
%O 0,77
%A _Jason Earls_, Jul 07 2003
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