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 A334542 #23 Jul 17 2021 03:47:13 %S A334542 1,2,3,4,5,6,7,8,9,58,85,375,666,1968,1998,3578,3665,3891,4658,4995, %T A334542 6675,7735,18434,27475,28784,46692,56763,58896,59577,59949,76965, %U A334542 186633,186673,795848,949968,965667,1339575,1587616,1929798,2765388,2989584,3674195,4763568,5762784,36741656,58988961,134369685,188959392 %N A334542 Numbers m such that m^2 = p^2 + k^2, with p > 0, where p = A007954(m) = the product of digits of m. %H A334542 Giovanni Resta, <a href="/A334542/b334542.txt">Table of n, a(n) for n = 1..140</a> (terms < 2*10^13) %e A334542 58 is a term as p = 5*8 = 40 and 58^2 = 3364 = 40^2 + 42^2. %e A334542 3891 is a term as p = 3*8*9*1 = 216 and 3891^2 = 15139881 = 216^2 + 3885^2. %o A334542 (PARI) isok(m) = my(p=vecprod(digits(m))); p && issquare(m^2 - p^2); \\ _Michel Marcus_, May 06 2020 %Y A334542 Cf. A007954, A000404, A078134, A334557, A334558. %Y A334542 Subsequence of A052382 (zeroless numbers). %K A334542 nonn,base %O A334542 1,2 %A A334542 _Scott R. Shannon_, May 05 2020