PROG
(MAGMAMagma) &cat[Reverse(Sort([pe[2]:pe in Factorisation(n)])):n in[1..76]]; // Jason Kimberley, Jun 13 2012
The OEIS is supported by the many generous donors to the OEIS Foundation.
Revision History for A212171
(Bold, blue-underlined text is an addition; faded, red-underlined text is aShowing entries 1-10 | older changes
Prime signature of n (nonincreasing version): row n of table lists positive exponents in canonical prime factorization of n, in nonincreasing order.
(history; published version)
(history; published version)
STATUS
reviewed
approved
STATUS
proposed
reviewed
STATUS
editing
proposed
PROG
(PARI) apply( {A212171_row(n)=vecsort(factor(n)[, 2]~, , 4)}, [1..40])\\ M. F. Hasler, Apr 19 2022
STATUS
proposed
editing
STATUS
editing
proposed
EXAMPLE
First rows of table read: 1; 1; 2; 1; 1,1; 1; 3; 2; 1,1; 1; 2,1;...
First rows of table read:
1;
1;
2;
1;
1,1;
1;
3;
2;
1,1;
1;
2,1;
...
STATUS
proposed
editing
STATUS
editing
proposed
COMMENTS
Differs from A124010 from a(23) on, corresponding to the factorisation factorization of 18 = 2^1*3^2 which is here listed as row 18 = [2, 1], but as [1, 2] (in the order of the prime factors) in A124010 and also in A118914 which lists the prime signatures in nondecreasing order (so that row 12 = 2^2*3^1 is also [1, 2]). - M. F. Hasler, Apr 08 2022
STATUS
proposed
editing
STATUS
editing
proposed