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 A358255 #20 Nov 06 2022 07:47:53 %S A358255 110,140,150,190,220,230,280,320,330,370,410,440,460,510,550,640,660, %T A358255 690,730,770,780,820,870,880,910,960,990,1010,1040,1050,1090,1130, %U A358255 1160,1180,1220,1230,1270,1300,1310,1360,1380,1410,1450,1540,1590,1630,1680,1720,1740,1770,1810,1860,1890,2020 %N A358255 Primitive Niven numbers ending with zero. %C A358255 A primitive Niven number (A356349) is a Niven number (A005349) that is not ten times another Niven number. %C A358255 For any k > 0, there exist terms with k trailing zeros; for example R_2^k * 10^k (where R = A002275), so this sequence is infinite. %C A358255 The smallest primitive Niven number ending with m zeros is A358256(m). %H A358255 Giovanni Resta, <a href="https://www.numbersaplenty.com/set/Harshad_number/">Harshad numbers</a>. %e A358255 150 is a term as 150 is a Niven number and 15 is not a Niven number. %e A358255 180 is not a term as 180 is a Niven number but 18 is also a Niven number. %t A358255 Select[10*Range[200], Divisible[#, (s = Plus @@ IntegerDigits[#])] && ! Divisible[#/10, s] &] (* _Amiram Eldar_, Nov 05 2022 *) %o A358255 (PARI) isniven(n) = n%sumdigits(n)==0; \\ A005349 %o A358255 isok(m) = !(m % 10) && isniven(m) && !isniven(m/10); \\ _Michel Marcus_, Nov 05 2022 %Y A358255 Cf. A002275, A005349. %Y A358255 Intersection of A008592 and A356349. %K A358255 nonn,base %O A358255 1,1 %A A358255 _Bernard Schott_, Nov 05 2022