|
|
A356234
|
|
Irregular triangle read by rows where row n is the ordered factorization of n into maximal gapless divisors.
|
|
11
|
|
|
2, 3, 4, 5, 6, 7, 8, 9, 2, 5, 11, 12, 13, 2, 7, 15, 16, 17, 18, 19, 4, 5, 3, 7, 2, 11, 23, 24, 25, 2, 13, 27, 4, 7, 29, 30, 31, 32, 3, 11, 2, 17, 35, 36, 37, 2, 19, 3, 13, 8, 5, 41, 6, 7, 43, 4, 11, 45, 2, 23, 47, 48, 49, 2, 25, 3, 17, 4, 13, 53, 54, 5, 11, 8
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
Row-products are the positive integers 1, 2, 3, ...
|
|
LINKS
|
|
|
EXAMPLE
|
The first 16 rows:
1 =
2 = 2
3 = 3
4 = 4
5 = 5
6 = 6
7 = 7
8 = 8
9 = 9
10 = 2 * 5
11 = 11
12 = 12
13 = 13
14 = 2 * 7
15 = 15
16 = 16
The factorization of 18564 is 18564 = 12*7*221, so row 18564 is {12,7,221}.
|
|
MATHEMATICA
|
primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
Table[Times@@Prime/@#&/@Split[primeMS[n], #1>=#2-1&], {n, 100}]
|
|
CROSSREFS
|
A003963 multiplies together the prime indices.
|
|
KEYWORD
|
nonn,tabf
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|