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A289172 Irregular triangle read by rows: row n lists terms m of A038566(n) such that A001221(m) = A051265(n), with a(1) = 1. 1
1, 1, 2, 3, 2, 3, 4, 5, 6, 3, 5, 7, 2, 4, 5, 7, 8, 3, 7, 9, 6, 10, 5, 7, 11, 6, 10, 12, 3, 5, 9, 11, 13, 14, 15, 6, 10, 12, 14, 15, 5, 7, 11, 13, 17, 6, 10, 12, 14, 15, 18, 3, 7, 9, 11, 13, 17, 19, 10, 20, 15, 21, 6, 10, 12, 14, 15, 18, 20, 21, 22, 5, 7, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Consider A051265(n), the largest value of A001221(m) for 1 <= m <= n such that gcd(m, n) = 1 (i.e., m is in the reduced residue system or RRS of n, or m is a totative of n). Row n of this sequence consists of m in RRS(n) such that omega(m) = A051265(n).

LINKS

Michael De Vlieger, Table of n, a(n) for the first 1000 rows, flattened

EXAMPLE

Triangle begins:

   n    T(n,m)                        A051265(n)

   1:   1                                     0

   2:   1                                     0

   3:   2                                     1

   4:   3                                     1

   5:   2    3    4                           1

   6:   5                                     1

   7:   6                                     2

   8:   3    5    7                           1

   9:   2    4    5    7    8                 1

  10:   3    7    9                           1

  11:   6   10                                2

  12:   5    7   11                           1

  13:   6   10   12                           2

  14:   3    5    9   11   13                 1

  15:  14                                     2

  16:  15                                     2

  17:   6   10   12   14   15                 2

  18:   5    7   11   13   17                 1

  19:   6   10   12   14   15   18            2

  20:   3    7    9   11   13   17   19       1

MATHEMATICA

Table[MaximalBy[#, Last][[All, 1]] &@ Map[{#, PrimeNu@ #} &, Cases[Range[n - 1], k_ /; CoprimeQ[n, k]]] /. {} -> {1}, {n, 30}] // Flatten (* Michael De Vlieger, Aug 11 2017 *)

CROSSREFS

Cf. A001221, A002110, A038566, A048597, A051250, A051265, A051266, A051267, A051268.

Sequence in context: A261323 A134986 A216209 * A215653 A286717 A162751

Adjacent sequences:  A289169 A289170 A289171 * A289173 A289174 A289175

KEYWORD

nonn,easy,tabf

AUTHOR

Michael De Vlieger, Aug 11 2017

STATUS

approved

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Last modified February 23 11:28 EST 2018. Contains 299571 sequences. (Running on oeis4.)