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Table read by rows: the n-th row is the list of numbers diagonally up and to the right of n in the natural numbers read by antidiagonals.
5

%I #13 Jul 02 2016 22:55:15

%S 2,4,5,4,7,8,7,9,8,7,11,12,11,13,12,11,14,13,12,11,16,17,16,18,17,16,

%T 19,18,17,16,20,19,18,17,16,22,23,22,24,23,22,25,24,23,22,26,25,24,23,

%U 22,27,26,25,24,23,22,29,30,29,31,30,29,32,31,30,29,33,32

%N Table read by rows: the n-th row is the list of numbers diagonally up and to the right of n in the natural numbers read by antidiagonals.

%H Peter Kagey, <a href="/A274079/b274079.txt">Table of n, a(n) for n = 1..10000</a>

%e A000027 read by antidiagonals is:

%e 1 2 4 7

%e 3 5 8

%e 6 9

%e ...

%e Thus:

%e Row 1: []

%e Row 2: []

%e Row 3: [2]

%e Row 4: []

%e Row 5: [4]

%e Row 6: [5, 4]

%e Row 7: []

%e Row 8: [7]

%e Row 9: [8, 7]

%t Table[Reverse@ Range[SelectFirst[Reverse@ #, # < n &] + 1, n - 1] - 1, {n, 2, 35}] &[Accumulate@ Range[0, 15] + 1] // Flatten (* _Michael De Vlieger_, Jun 10 2016, Version 10 *)

%o (Haskell)

%o a274079 n = a274079_list !! (n - 1)

%o a274079_list = concatMap a274079_row [1..]

%o a274079_tabf = map a274079_row [1..]

%o a274079_row n = [n-1, n-2..n - a002262 (n - 1)]

%Y Cf. A000027, A269526, A273823, A273824, A273825, A274080.

%K nonn,tabf

%O 1,1

%A _Peter Kagey_, Jun 09 2016