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A273824 Table read by rows: the n-th row is the list of numbers above n in the table of natural numbers read by antidiagonals. 5
1, 2, 3, 1, 4, 5, 2, 6, 3, 1, 7, 8, 4, 9, 5, 2, 10, 6, 3, 1, 11, 12, 7, 13, 8, 4, 14, 9, 5, 2, 15, 10, 6, 3, 1, 16, 17, 11, 18, 12, 7, 19, 13, 8, 4, 20, 14, 9, 5, 2, 21, 15, 10, 6, 3, 1, 22, 23, 16, 24, 17, 11, 25, 18, 12, 7, 26, 19, 13, 8, 4, 27, 20, 14, 9, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Peter Kagey, Table of n, a(n) for n = 1..10000

EXAMPLE

A000027 read by antidiagonals is:

1 2 4 7

3 5 8

6 9

...

Thus:

Row 1: []

Row 2: []

Row 3: [1]

Row 4: []

Row 5: [2]

Row 6: [3, 1]

Row 7: []

Row 8: [4]

Row 9: [5, 2]

MATHEMATICA

nn = 35; t = Transpose@ Table[(n^2 - n)/2 + Accumulate@ Range[n - 1, n + Ceiling[(Sqrt[9 + 8 nn] - 3)/2]] + 1, {n, Ceiling[(Sqrt[9 + 8 nn] - 3)/2] + 1}]; Table[Reverse@ Take[t[[#1]], #2 - 1] & @@ Flatten@ Position[t, n], {n, nn}] // Flatten (* Michael De Vlieger, Jun 10 2016 *)

PROG

(Haskell)

a273824 n = genericIndex a273824_list (n - 1)

a273824_list = concatMap a273824_row [1..]

a273824_tabf = map a273824_row [1..]

a273824_row n

  | a_i == 0  = []

  | otherwise = a_i : a273824_row a_i where

    a_i = a271439 (n - 1)

CROSSREFS

Cf. A000027, A269526, A271439, A273823, A273825, A274079, A274080.

Sequence in context: A131225 A221919 A341971 * A137671 A256946 A285715

Adjacent sequences:  A273821 A273822 A273823 * A273825 A273826 A273827

KEYWORD

nonn,tabf

AUTHOR

Peter Kagey, Jun 08 2016

STATUS

approved

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Last modified April 23 06:38 EDT 2021. Contains 343201 sequences. (Running on oeis4.)