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 A248147 Table read by rows: n-th row contains all consecutive subsets of the first n primes in their natural order. 5
 2, 2, 3, 2, 3, 2, 3, 5, 2, 3, 3, 5, 2, 3, 5, 2, 3, 5, 7, 2, 3, 3, 5, 5, 7, 2, 3, 5, 3, 5, 7, 2, 3, 5, 7, 2, 3, 5, 7, 11, 2, 3, 3, 5, 5, 7, 7, 11, 2, 3, 5, 3, 5, 7, 5, 7, 11, 2, 3, 5, 7, 3, 5, 7, 11, 2, 3, 5, 7, 11, 2, 3, 5, 7, 11, 13, 2, 3, 3, 5, 5, 7, 7, 11 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A000292(n) = length of n-th row, whereas A000217(n) = number of all consecutive subsets of numbers 1..n; T(n,k) = A000040(A248141(n,k)), 1 <= k <= A000292(n). LINKS Reinhard Zumkeller, Rows n = 1..20 of triangle, flattened EXAMPLE . 1: 2 . 2: 2,3,2,3 . 3: 2,3,5,2,3,3,5,2,3,5 . 4: 2,3,5,7,2,3,3,5,5,7,2,3,5,3,5,7,2,3,5,7 . 5: 2,3,5,7,11,2,3,3,5,5,7,7,11,2,3,5,3,5,7,5,7,11,2,3,5,7,3,5,7,11,... rows concatenated from: . 1: [2] . 2: [2] [3] [2,3] . 3: [2] [3] [5] [2,3] [3,5] [2,3,5] . 4: [2] [3] [5] [7] [2,3] [3,5] [5,7] [2,3,5] [3,5,7] [2,3,5,7] . 5: [2] [3] [5] [7] [11] [2,3] [3,5] [5,7] [7,11] [2,3,5] [3,5,7] ... PROG (Haskell) import Data.List (group) a248147 n k = a248147_tabf !! (n-1) !! (k-1) a248147_row n = a248147_tabf !! (n-1) a248147_tabf = map concat psss where psss = iterate f [[2]] where f pss = group (h \$ last pss) ++ map h pss h ws = ws ++ [a151800 \$ last ws] CROSSREFS Cf. A151800, A000292, A000217, A248164, A248141. Sequence in context: A099427 A059964 A308050 * A087458 A052180 A065151 Adjacent sequences: A248144 A248145 A248146 * A248148 A248149 A248150 KEYWORD nonn,tabf AUTHOR Reinhard Zumkeller, Oct 02 2014 STATUS approved

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Last modified June 15 10:19 EDT 2024. Contains 373407 sequences. (Running on oeis4.)