login
A365423
Odd numbers k for which k and A163511(k) have the same prime signature.
3
3, 7, 31, 45, 55, 111, 119, 123, 127, 175, 207, 247, 253, 447, 567, 895, 927, 945, 957, 959, 987, 1005, 1007, 1017, 1503, 1519, 1887, 1919, 1983, 2013, 2023, 2031, 2037, 2045, 3325, 3567, 3835, 3839, 3927, 3965, 4015, 4025, 4029, 4031, 4063, 4085, 4087, 5887, 7035, 7095, 7119, 7163, 7167, 7679, 7791, 7839, 7917, 7931
OFFSET
1,1
COMMENTS
See comments in A364297.
PROG
(PARI)
A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };
A163511(n) = if(!n, 1, my(p=2, t=1); while(n>1, if(!(n%2), (t*=p), p=nextprime(1+p)); n >>= 1); (t*p));
A365421(n) = (A046523(A163511(n))==A046523(n));
isA365423(n) = ((n%2)&&A365421(n));
CROSSREFS
Odd terms in A365422.
Cf. A000668 (subsequence), A046523, A163511, A278531, A364297, A365421.
Sequence in context: A034915 A145479 A077315 * A080168 A183075 A292890
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 04 2023
STATUS
approved