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A329647
Bitwise-XOR of exponents of prime factors of A108951(n), where A108951 is fully multiplicative with a(prime(i)) = prime(i)# = Product_{i=1..i} A000040(i).
5
0, 1, 0, 2, 1, 3, 0, 3, 0, 2, 1, 2, 0, 3, 1, 4, 1, 1, 0, 3, 0, 2, 1, 5, 2, 3, 0, 2, 0, 0, 1, 5, 1, 2, 3, 6, 0, 3, 0, 4, 1, 1, 0, 3, 1, 2, 1, 4, 0, 3, 1, 2, 0, 7, 2, 5, 0, 3, 1, 7, 0, 2, 0, 6, 3, 0, 1, 3, 1, 2, 0, 7, 1, 3, 2, 2, 1, 1, 0, 5, 0, 2, 1, 6, 2, 3, 0, 4, 0, 6, 0, 3, 1, 2, 3, 7, 1, 1, 1, 4, 0, 0, 1, 5, 3
OFFSET
1,4
COMMENTS
Positions of records are: 1, 2, 4, 6, 16, 24, 36, 54, 256, 384, 576, 864, 1296, 1944, 2916, 4374, 65536, ..., conjectured also to be the positions of the first occurrence of each n.
FORMULA
a(n) = A268387(A108951(n)).
a(n) <= A329616(n).
PROG
(PARI)
A034386(n) = prod(i=1, primepi(n), prime(i));
A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A034386(f[i, 1])^f[i, 2]) }; \\ From A108951
A268387(n) = if(n>1, fold(bitxor, factor(n)[, 2]), 0);
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 18 2019
STATUS
approved