OFFSET
1,2
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..10000
PROG
(PARI)
A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ Using code of Michel Marcus
(Python)
from sympy import factorint, nextprime
from operator import mul
def a048673(n):
f = factorint(n)
return 1 if n==1 else (1 + reduce(mul, [nextprime(i)**f[i] for i in f]))/2
def a(n): return a048673(n)%4 # Indranil Ghosh, Jun 12 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 31 2017
STATUS
approved