The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A304194

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A304194

Numbers k such that k = Product (p_j^e_j) = Product (pi(p_j)*p_j), where pi() = A000720.
(history; published version)

#12 by Susanna Cuyler at Wed May 09 23:03:50 EDT 2018

STATUS

proposed

approved

#11 by Michel Marcus at Tue May 08 03:04:30 EDT 2018

STATUS

editing

proposed

#10 by Michel Marcus at Tue May 08 03:04:22 EDT 2018

PROG

(PARI) isok(n) = {my(f=factor(n)); prod(k=1, #f~, primepi(f[k, 1])*f[k, 1]) == n; } \\ Michel Marcus, May 08 2018

STATUS

proposed

editing

#9 by Michel Marcus at Tue May 08 02:58:43 EDT 2018

STATUS

editing

proposed

#8 by Michel Marcus at Tue May 08 02:58:11 EDT 2018

EXAMPLE

9900 is in the sequence a term because 9900 = 2^2 * 3^2 * 5^2 * 11 = prime(1)^2 * prime(2)^2 * prime(3)^2 * prime(5) = 1 * prime(1) * 2 * prime(2) * 3 * prime(3) * 5 * prime(5).

STATUS

proposed

editing

#7 by Ilya Gutkovskiy at Mon May 07 18:39:24 EDT 2018

STATUS

editing

proposed

#6 by Ilya Gutkovskiy at Mon May 07 18:39:12 EDT 2018

CROSSREFS

Cf. A000720, A003557, A005117, A007947, A008478, A033286, A046022, A048768, A078779, A109298, A156061.

STATUS

proposed

editing

#5 by Ilya Gutkovskiy at Mon May 07 18:37:03 EDT 2018

STATUS

editing

proposed

#4 by Ilya Gutkovskiy at Mon May 07 18:36:40 EDT 2018

NAME

Numbers k such that k = Product (p_j^e_j) = Product (pi(p_j)*p_j), where pi() = A000720.

#3 by Ilya Gutkovskiy at Mon May 07 18:21:00 EDT 2018

EXAMPLE

9900 is in the sequence because 9900 = 2^2 * 3^2 * 5^2 * 11 = prime(1)^2 * prime(2)^2 * prime(3)^2 * prime(5) = 1 * prime(1) * 2 * prime(2) * 3 * prime(3) * 5 * prime(5).