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A361469
a(n) = bigomega(A249670(A003961(n))).
1
0, 3, 3, 3, 4, 4, 4, 7, 3, 7, 3, 4, 4, 5, 7, 6, 4, 6, 5, 7, 7, 6, 4, 6, 4, 5, 7, 5, 6, 8, 3, 9, 6, 7, 8, 6, 4, 6, 7, 11, 4, 8, 6, 4, 7, 5, 5, 7, 4, 5, 5, 3, 5, 8, 5, 9, 8, 9, 3, 8, 4, 6, 7, 7, 8, 7, 6, 7, 5, 9, 3, 8, 6, 5, 7, 6, 7, 8, 5, 10, 6, 7, 5, 6, 8, 7, 9, 10, 4, 10, 8, 5, 6, 6, 9, 10, 4, 7, 6, 5, 5, 6, 6, 7, 11
OFFSET
1,2
COMMENTS
Conjecture: There are no 1's in this sequence. If true, it would imply that there are no odd terms in A065997.
The first n with a(n) = 2 is 1684804. Note that A003961(1684804) = 5659641 is so far the only known odd term in A247086.
FORMULA
PROG
(PARI)
A003961(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); }; \\ From A003961
A249670(n) = { my(ab = sigma(n)/n); numerator(ab)*denominator(ab); };
A361469(n) = bigomega(A249670(A003961(n)));
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Mar 20 2023
STATUS
approved