This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A269247 #15 Mar 22 2020 01:59:38
%S A269247 0,0,0,1,0,0,0,0,0,1,0,0,1,1,1,1,0,0,0,0,0,0,0,1,0,0,2,0,0,0,1,1,1,1,
%T A269247 0,1,0,0,1,0,0,0,1,2,0,0,1,0,0,1,0,0,0,2,1,1,1,0,0,1,0,0,0,1,0,1,1,1,
%U A269247 0,0,0,1,1,1,0,1,1,0,1,0,0,0,0,3,1,0,0,0,1,1,1,2,2,1,0,2,1,1,0,1,0
%N A269247 Number of times the digit 7 appears in the decimal expansion of n^3.
%C A269247 The cubes corresponding to the first occurrence of 1, 2, 3, ... are listed in A036534, i.e., A036534(n)^(1/3) = A048372(n) is the index of the first occurrence of n.
%e A269247 0^3 = 0, 1^3 = 1, 2^3 = 8 and 4^3 = 64 all have a(0) = a(1) = a(2) = a(4) = 0 digits '7'.
%e A269247 3^3 = 27 has a(3) = 1 digit '7'.
%t A269247 Table[DigitCount[n^3, 10, 7], {n, 0, 100}] (* _Robert Price_, Mar 21 2020 *)
%o A269247 (PARI) A269247(n)=#select(t->t==7,digits(n^3))
%Y A269247 Cf. A036534 and A036527 - A036536; A048372 and A048365 - A048374.
%Y A269247 Analog for the other digits 0, 1, ..., 9: A269250, A269241, A269242, A269243, A269244, A269245, A269246, A269247, A269248, A269249.
%Y A269247 Analog for squares: A086015 (digit 7), and A086008 - A086017 for digits 0 - 9.
%K A269247 nonn,base
%O A269247 0,27
%A A269247 _M. F. Hasler_, Feb 20 2016