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 A187769 Triangle read by rows: equivalence classes of natural numbers, where numbers are equivalent when having equal numbers of zeros and ones in binary representation, respectively. 4
 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 11, 13, 14, 15, 16, 17, 18, 20, 24, 19, 21, 22, 25, 26, 28, 23, 27, 29, 30, 31, 32, 33, 34, 36, 40, 48, 35, 37, 38, 41, 42, 44, 49, 50, 52, 56, 39, 43, 45, 46, 51, 53, 54, 57, 58, 60, 47, 55, 59, 61, 62, 63, 64, 65, 66 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Row lengths are given by Pascal's triangle (cf. A007318), seen as flattened sequence, or for n > 0: length of n-th row = A007318(A003056(n-1),A002262(n-1)); 1 <= i < j <= length of n-th row: A023416(T(n,i)) = A023416(T(n,j)), A000120(T(n,i)) = A000120(T(n,j)) and A070939(T(n,i)) = A070939(T(n,j)); the table provides a permutation of the natural numbers when seen as flattened sequence. LINKS Reinhard Zumkeller, Rows n = 0..78 of triangle, flattened - all terms < 2^12 Reinhard Zumkeller, Illustration of initial terms EXAMPLE See link. PROG (Haskell) import List (elemIndices) a187769 n k = a187769_tabf !! n !! k a187769_row n = a187769_tabf !! n a187769_tabf =  : [elemIndices (b, len - b) \$    takeWhile ((<= len) . uncurry (+)) \$ zip a000120_list a023416_list |    len <- [1 ..], b <- [1 .. len]] a187769_list = concat a187769_tabf CROSSREFS Rows of A187786, duplicates removed; cf. A099627 (left edge), A023758 (right edge). Sequence in context: A031297 A239086 A306866 * A209862 A209861 A287929 Adjacent sequences:  A187766 A187767 A187768 * A187770 A187771 A187772 KEYWORD nonn,base,tabf AUTHOR Reinhard Zumkeller, Jan 05 2013 STATUS approved

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Last modified September 30 03:54 EDT 2020. Contains 337434 sequences. (Running on oeis4.)