OFFSET
1,7
COMMENTS
Starting from x=n, iterate the map x -> A332893(x) which divides even numbers by 2, and for odd n, changes every 4k+1 prime in the prime factorization to 4k+3 prime and vice versa (except 3 --> 2), like in A332819. a(n) counts the numbers of the form 4k+3 encountered until 1 has been reached. The count includes also n itself if it is of the form 4k+3 (A004767).
In other words, locate the node which contains n in binary tree A332815 and traverse from that node towards the root, counting all numbers of the form 4k+3 that occur on the path.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
FORMULA
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Mar 04 2020
STATUS
approved