

A328446


Table read by rows: the nth 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 nth row has length A309978(n) for n > 1.


LINKS

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


EXAMPLE

Table begins
n  nth 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(nd, d) == nd), row = concat(row, d))); concat(row, n1); }
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



