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 A371728 #46 Apr 01 2025 19:03:54 %S A371728 9,13,19,31,40,46,54,63,70,81,88,97,106,112,121,130,136,148,154,162, %T A371728 171,180,187,193,205,211,220,229,235,244,253,262,271,277,286,297,301, %U A371728 310,319,331,334,343,355,360,367,378,388,396 %N A371728 a(n) is the largest number that is the digit sum of an n-digit square number. %C A371728 a(n) appears to be approximately equal to (33*n-11)/4. %H A371728 Shouen Wang, <a href="https://bbs.emath.ac.cn/thread-19296-1-1.html">Chinese BBS: How many of these A's are there?</a> %e A371728 a(6) = 46 because 46 is the largest digital sum encountered among all 6-digit squares (698896, 779689, 877969). %t A371728 Array[Max@Map[Total@IntegerDigits[#^2] &, Range[Floor@Sqrt[10^(#)]], Floor@Sqrt[10^(# + 1) - 1]] &, 15] %Y A371728 Cf. A004159, A049415, A069665, A069666. %Y A371728 Cf. A056991, A348300, A379298. %K A371728 nonn,base,more %O A371728 1,1 %A A371728 _Zhining Yang_, Apr 04 2024 %E A371728 a(22)-a(48) from _Zhao Hui Du_, Apr 05 2024 %E A371728 a(49)-a(62) from _Zhining Yang_, May 08 2024 %E A371728 a(63)-a(64) from _Zhining Yang_, May 23 2024 %E A371728 Incorrect a(61) and unverified a(49) onward deleted by _Zhining Yang_, Mar 03 2025