A279773 Numbers n such that the sum of digits of 3n equals 6.
2, 5, 8, 11, 14, 17, 20, 35, 38, 41, 44, 47, 50, 68, 71, 74, 77, 80, 101, 104, 107, 110, 134, 137, 140, 167, 170, 200, 335, 338, 341, 344, 347, 350, 368, 371, 374, 377, 380, 401, 404, 407, 410, 434, 437, 440, 467, 470, 500, 668, 671, 674, 677, 680, 701
Offset: 1
Crossrefs
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).
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.
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).
Programs
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Mathematica
Select[Range@ 720, Total@ IntegerDigits[3 #] == 6 &] (* Michael De Vlieger, Dec 23 2016 *)
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PARI
select( is(n)=sumdigits(3*n)==6, [1..999])
Comments