A325567 a(1) = 1; for n > 1, a(n) is the largest proper divisor d of n such that A048720(A065621(d),n/d) is equal to n.

1, 1, 1, 2, 1, 2, 1, 4, 3, 2, 1, 4, 1, 2, 1, 8, 1, 6, 1, 4, 3, 2, 1, 8, 1, 2, 1, 4, 1, 2, 1, 16, 11, 2, 5, 12, 1, 2, 1, 8, 1, 6, 1, 4, 3, 2, 1, 16, 7, 2, 1, 4, 1, 2, 1, 8, 1, 2, 1, 4, 1, 2, 1, 32, 13, 22, 1, 4, 1, 10, 1, 24, 1, 2, 5, 4, 1, 2, 1, 16, 1, 2, 1, 12, 1, 2, 1, 8, 1, 6, 1, 4, 3, 2, 1, 32, 1, 14, 1, 4, 1, 2, 1, 8, 7

Offset: 1

Author

Antti Karttunen, May 09 2019

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16383
• Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537

Crossrefs

Cf. A032742, A048720, A065621, A115872, A325565, A325566, A325568.

Programs

PARI

A048720(b,c) = fromdigits(Vec(Pol(binary(b))*Pol(binary(c)))%2, 2);
A065621(n) = bitxor(n-1,n+n-1);
A325567(n) = if(1==n,n,fordiv(n,d,if((d>1)&&A048720(A065621(n/d),d)==n,return(n/d))));