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 A279773 #10 Dec 23 2016 21:42:32 %S A279773 2,5,8,11,14,17,20,35,38,41,44,47,50,68,71,74,77,80,101,104,107,110, %T A279773 134,137,140,167,170,200,335,338,341,344,347,350,368,371,374,377,380, %U A279773 401,404,407,410,434,437,440,467,470,500,668,671,674,677,680,701 %N A279773 Numbers n such that the sum of digits of 3n equals 6. %C A279773 Inspired by A088405 = A052217/3 and A279769 (the analog for 9). %t A279773 Select[Range@ 720, Total@ IntegerDigits[3 #] == 6 &] (* _Michael De Vlieger_, Dec 23 2016 *) %o A279773 (PARI) select( is(n)=sumdigits(3*n)==6, [1..999]) %Y A279773 Cf. A007953 (digital sum), A279772 (sumdigits(2n) = 4), A279774 (sumdigits(4n) = 8), A279775 (sumdigits(5n) = 10), A279776 (sumdigits(6n) = 12), A279770 (sumdigits(7n) = 14), A279768 (sumdigits(8n) = 16), A279769 (sumdigits(9n) = 18), A279777 (sumdigits(9n) = 27). %Y A279773 Digital sum of m*n equals m: A088404 = A069537/2, A088405 = A052217/3, A088406 = A063997/4, A088407 = A069540/5, A088408 = A062768/6, A088409 = A063416/7, A088410 = A069543/8. %Y A279773 Cf. A005349 (Niven or Harshad numbers), A245062 (arranged in rows by digit sums). %Y A279773 Numbers with given digital sum: A011557 (1), A052216 (2), A052217 (3), A052218 (4), A052219 (5), A052220 (6), A052221 (7), A052222 (8), A052223 (9), A052224 (10), A166311 (11), A235151 (12), A143164 (13), A235225 (14), A235226 (15), A235227 (16), A166370 (17), A235228 (18), A166459 (19), A235229 (20). %K A279773 nonn,easy,base %O A279773 1,1 %A A279773 _M. F. Hasler_, Dec 23 2016