OFFSET
0,3
COMMENTS
Following A285332, also this sequence can be represented in a form of a binary tree:
0
|
...................1...................
2 2
3......../ \........4 4......../ \........3
/ \ / \ / \ / \
/ \ / \ / \ / \
/ \ / \ / \ / \
6 4 9 6 5 8 8 4
15 8 12 5 14 10 27 8 10 6 25 12 7 16 16 5
etc.
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..1023
FORMULA
PROG
(PARI)
A019565(n) = {my(j, v); factorback(Mat(vector(if(n, #n=vecextract(binary(n), "-1..1")), j, [prime(j), n[j]])~))}; \\ This function from M. F. Hasler
A048675(n) = my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; \\ Michel Marcus, Oct 10 2016
A007947(n) = factorback(factorint(n)[, 1]); \\ From Andrew Lelechenko, May 09 2014
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Antti Karttunen, Apr 19 2017
STATUS
approved