cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A325573 Odd numbers n that have divisor d > 1 such that A048720(A065621(d),n/d) = n.

Original entry on oeis.org

9, 21, 33, 35, 45, 49, 65, 75, 93, 105, 129, 133, 135, 153, 155, 161, 165, 189, 195, 217, 225, 259, 273, 279, 297, 309, 315, 341, 345, 381, 385, 403, 441, 465, 513, 525, 527, 561, 567, 585, 589, 597, 611, 621, 635, 645, 651, 681, 693, 705, 713, 729, 765, 775, 793, 819, 837, 889, 899, 945, 961, 1025, 1029, 1035, 1057, 1065
Offset: 1

Views

Author

Antti Karttunen, May 10 2019

Keywords

Crossrefs

Subsequence of A071904 and of A325572.

Programs

  • PARI
    A048720(b,c) = fromdigits(Vec(Pol(binary(b))*Pol(binary(c)))%2, 2);
    A065621(n) = bitxor(n-1,n+n-1);
    isA325573(n) = ((n%2)&&fordiv(n,d,if(A048720(A065621(n/d),d)==n,return(d