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 A316487 #19 Feb 28 2024 10:48:18 %S A316487 2778889,4695889,5678689,5697769,5938969,6568969,6589489,6848689, %T A316487 6895876,7974976,7997584,8779369,9878449,9966649,299739969,377796969, %U A316487 396686889,458687889,467986689,487658889,488984769,496977849,538889796,557998884,559984896,569967876 %N A316487 Squares whose arithmetic mean of digits is 7 (i.e., the sum of digits is 7 times the number of digits). %C A316487 Each term's number of digits is in A056991 (Numbers with digital root 1, 4, 7, or 9). For every term k in A056991, this sequence contains at least one k-digit term, with the exception of k=1 and k=4. (See A316480.) %H A316487 Jon E. Schoenfield, <a href="/A316487/b316487.txt">Table of n, a(n) for n = 1..10000</a> %e A316487 17313^2 = 299739969, a 9-digit number whose digit sum is 2+9+9+7+3+9+9+6+9 = 63 = 7*9, so 299739969 is a term. %e A316487 43474^2 = 1889988676, a 10-digit number whose digit sum is 1+8+8+9+9+8+8+6+7+6 = 70 = 7*10, so 1889988676 is a term. %Y A316487 Cf. A056991, A069711, A316480. %Y A316487 Intersection of A000290 and A061424. - _Michel Marcus_, Jul 06 2018 %K A316487 nonn,base %O A316487 1,1 %A A316487 _Jon E. Schoenfield_, Jul 04 2018