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 A279770 #11 Dec 23 2016 21:41:37 %S A279770 11,38,47,56,65,74,83,92,101,110,119,155,164,182,191,209,218,236,245, %T A279770 263,272,299,308,317,326,335,344,353,362,380,389,416,434,452,461,470, %U A279770 479,488,506,515,533,560,578,587,596,605,623,632,650,659,686,722,731 %N A279770 Numbers n such that the sum of digits of 7n equals 14. %C A279770 Inspired by A088409 = A063416/7 and A279769 (the analog for 9). %t A279770 Select[Range@ 731, Total@ IntegerDigits[7 #] == 14 &] (* _Michael De Vlieger_, Dec 23 2016 *) %o A279770 (PARI) is(n)=sumdigits(7*n)==14 %Y A279770 Cf. A007953 (digital sum), A279772 (sumdigits(2n) = 4), A279773 (sumdigits(3n) = 6), A279774 (sumdigits(4n) = 8), A279775 (sumdigits(5n) = 10), A279776 (sumdigits(6n) = 12), A279768 (sumdigits(8n) = 16), A279769 (sumdigits(9n) = 18), A279777 (sumdigits(9n) = 27). %Y A279770 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 A279770 Cf. A005349 (Niven or Harshad numbers), A245062 (arranged in rows by digit sums). %Y A279770 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 A279770 nonn,easy,base %O A279770 1,1 %A A279770 _M. F. Hasler_, Dec 23 2016