# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a325309 Showing 1-1 of 1 %I A325309 #14 Sep 10 2019 21:49:29 %S A325309 1,2,1,4,2,1,6,3,2,1,8,4,3,2,1,10,6,4,3,2,1,12,8,6,4,3,2,1,16,9,8,5,4, %T A325309 3,2,1,18,10,9,6,5,4,3,2,1,20,12,12,8,6,5,4,3,2,1,21,15,16,10,10,6,5, %U A325309 4,3,2,1,24,16,18,12,12,7,6,5,4,3,2,1,32,18 %N A325309 Square array read by downward antidiagonals: A(n, k) is the k-th Niven number (or Harshad number) in base n. %H A325309 Wikipedia, Harshad number %e A325309 The array starts as follows: %e A325309 1, 2, 4, 6, 8, 10, 12, 16, 18, 20, 21, 24, 32, 34, 36, 40, 42, 48, 55, 60 %e A325309 1, 2, 3, 4, 6, 8, 9, 10, 12, 15, 16, 18, 20, 21, 24, 25, 27, 28, 30, 32 %e A325309 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 20, 21, 24, 28, 30, 32, 33, 35, 36, 40 %e A325309 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 18, 20, 24, 25, 26, 27, 28, 30, 32 %e A325309 1, 2, 3, 4, 5, 6, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 42, 44, 45, 48 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 14, 15, 16, 18, 21, 24, 27, 28, 30, 32 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 14, 16, 21, 24, 28, 32, 35, 40, 42, 48, 49, 56 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 16, 18, 20, 24, 27, 28, 30, 32, 36 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 18, 20, 21, 24, 27, 30, 36, 40, 42 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 20, 22, 24, 25, 30, 33, 35 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 22, 24, 33, 36, 44, 48, 55, 60 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 24, 26, 27 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 26, 28, 39, 42, 52, 56 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 21, 28, 30, 32 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 30, 32 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 24 %e A325309 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 34, 36 %o A325309 (PARI) row(n, terms) = my(i=0); for(x=1, oo, if(i >= terms, break); if(x%sumdigits(x, n)==0, print1(x, ", "); i++)) %o A325309 array(rows, cols) = for(x=2, rows+1, row(x, cols); print("")) %o A325309 array(18, 20) \\ Print initial 18 rows and 20 columns of array %Y A325309 Cf. A049445 (row 2), A064150 (row 3), A064438 (row 4), A064481 (row 5), A245802 (row 8), A005349 (row 10). %Y A325309 Cf. A005349. %K A325309 nonn,tabl,base,easy %O A325309 2,2 %A A325309 _Felix Fröhlich_, Sep 06 2019 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE