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A328446 Table read by rows: the n-th row gives the nonnegative integers k such that n - k is a power of k. 2
0, 1, 2, 2, 3, 4, 2, 3, 5, 6, 4, 7, 8, 2, 5, 9, 10, 3, 6, 11, 12, 7, 13, 14, 8, 15, 16, 2, 9, 17, 18, 4, 10, 19, 20, 11, 21, 22, 12, 23, 24, 13, 25, 26, 14, 27, 28, 3, 5, 15, 29, 30, 16, 31, 32, 2, 17, 33, 34, 18, 35, 36, 19, 37, 38, 20, 39, 40, 6, 21, 41, 42, 22 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

The n-th row has length A309978(n) for n > 1.

LINKS

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

EXAMPLE

Table begins

   n | n-th row

  ---+----------

   1 | 0

   2 | 1

   3 | 2

   4 | 2, 3

   5 | 4

   6 | 2, 3, 5

   7 | 6

   8 | 4, 7

   9 | 8

  10 | 2, 5, 9

  11 | 10

  12 | 3, 6, 11

  13 | 12

  14 | 7, 13

  15 | 14

  16 | 8, 15

  17 | 16

  18 | 2, 9, 17

For n = 10 the 10th row is 2, 5, 9 because

10 - 2 = 2^3,

10 - 5 = 5^1, and

10 - 9 = 9^0.

PROG

(PARI) row(n) = {if (n==1, return ([0])); my(row = vector(0)); fordiv(n, d, if ((d>1) && (d<n) && (d^valuation(n-d, d) == n-d), row = concat(row, d))); concat(row, n-1); }

tabf(nn) = {for (n=1, nn, print(row(n)); ); } \\ Michel Marcus, Oct 16 2019

CROSSREFS

Cf. A307092, A309978.

Sequence in context: A159978 A230546 A286617 * A257062 A098223 A114892

Adjacent sequences:  A328443 A328444 A328445 * A328447 A328448 A328449

KEYWORD

nonn,tabf

AUTHOR

Peter Kagey, Oct 15 2019

STATUS

approved

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Last modified February 22 17:14 EST 2020. Contains 332140 sequences. (Running on oeis4.)