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 A048794 Subsets of natural numbers arranged in standard statistical (or Yates) order. 3
 0, 1, 2, 12, 3, 13, 23, 123, 4, 14, 24, 124, 34, 134, 234, 1234, 5, 15, 25, 125, 35, 135, 235, 1235, 45, 145, 245, 1245, 345, 1345, 2345, 12345, 6, 16, 26, 126, 36, 136, 236, 1236, 46, 146, 246, 1246, 346, 1346, 2346, 12346, 56, 156, 256, 1256, 356, 1356 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS a(2^n) = n+1. - Reinhard Zumkeller, Nov 16 2013 REFERENCES S. Hedayat, N. J. A. Sloane and J. Stufken, Orthogonal Arrays, Springer-Verlag, NY, 1999, p. 249. LINKS Reinhard Zumkeller, Table of n, a(n) for n = 0..10000 FORMULA Constructed recursively: subsets that include n are obtained by appending n to all earlier subsets. EXAMPLE empty; 1; 2; 1 2; 3; 1 3; 2 3; 1 2 3;... MATHEMATICA nmax = 6; s[0] = {{}}; s[n_] := s[n] = Join[s[n-1], Append[#, n]& /@ s[n-1]]; FromDigits /@ s[nmax] (* Jean-François Alcover, Nov 15 2011 *) PROG (C:) #include #include #define USAGE "Usage: 'A048794 num' where num is the largest number to use creating sets.\n" #define MAX_NUM 10 #define MAX_ROW 1024 int main(int argc, char *argv[]) { unsigned char a[MAX_ROW][MAX_NUM]; signed short old_row, new_row, i, j, end; if (argc < 2) { fprintf(stderr, USAGE); return EXIT_FAILURE; } end = atoi(argv[1]); end = (end > MAX_NUM) ? MAX_NUM: end; for (i = 0; i < MAX_ROW; i++) for ( j = 0; j < MAX_NUM; j++) a[i][j] = 0; a[1][0] = '1'; new_row = 2; for (i = 2; i <= end; i++) { sprintf(&a[new_row++ ][0], "%d", i); for (old_row = 1; a[old_row][0] != (i+48); old_row++) { sprintf(&a[new_row++ ][0], "%s%d", &a[old_row][0], i); } } fprintf(stdout, "Values: 0"); for (i = 1; a[i][0] != 0; i++) fprintf(stdout, ", %s", &a[i][0]); fprintf(stdout, "\n"); return EXIT_SUCCESS; } (Haskell) a048794 n = a048794_list !! n a048794_list = map (read . concatMap show) a048793_tabf :: [Integer] -- Reinhard Zumkeller, Nov 16 2013 CROSSREFS Cf. A048793. Sequence in context: A072484 A337918 A113698 * A275841 A224841 A317206 Adjacent sequences:  A048791 A048792 A048793 * A048795 A048796 A048797 KEYWORD nonn,easy,nice,base AUTHOR EXTENSIONS More terms from Larry Reeves (larryr(AT)acm.org), Apr 11 2000 Keyword base added by Reinhard Zumkeller, Nov 16 2013 STATUS approved

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Last modified April 20 06:59 EDT 2021. Contains 343125 sequences. (Running on oeis4.)