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 A346774 #19 Aug 05 2021 11:15:57 %S A346774 88,150,210,212,338,340,470,580,670,880,940,1050,1060,1062,1070,1080, %T A346774 1088,1090,1488,1510,1512,1820,1830,1838,1840,2110,2112,2120,2350, %U A346774 2360,2362,2570,2580,2588,2780,2790,2970,3150,3160,3320,3330,3350,3360,3362,3370,3380,3388,3390,3410 %N A346774 Numbers whose square starts and ends with exactly 2 identical digits. %C A346774 The terminal digits are 00 or 44. %e A346774 150 is a term because 150^2 = 22500. %e A346774 212 is a term because 212^2 = 44944 (smallest square with 2 times two 4's). %e A346774 2788 is not a term because 2788^2 = 7772944. %t A346774 Select[Range[32, 3500], (d = IntegerDigits[#^2])[[1]] == d[[2]] != d[[3]] && d[[-1]] == d[[-2]] != d[[-3]] &] (* _Amiram Eldar_, Aug 03 2021 *) %o A346774 (Python) %o A346774 def ok(n): %o A346774 s = str(n*n) %o A346774 if len(s) < 4: return False # there are no ok squares with < 4 digits %o A346774 return s[0] == s[1] != s[2] and s[-1] == s[-2] != s[-3] %o A346774 print(list(filter(ok, range(3411)))) # _Michael S. Branicky_, Aug 03 2021 %Y A346774 Subsequence of A346678. %Y A346774 Cf. A123912, A186438, A186439. %K A346774 nonn,base %O A346774 1,1 %A A346774 _Bernard Schott_, Aug 03 2021