A365423 Odd numbers k for which k and A163511(k) have the same prime signature.

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

Author

Antti Karttunen, Sep 04 2023

Keywords

• nonn

Comments

See comments in A364297.

Crossrefs

Odd terms in A365422.

Cf. A000668 (subsequence), A046523, A163511, A278531, A364297, A365421.

Programs

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));