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.

A131826 a(n) is the unique solution to Cototient(x) = A131825(n).

Original entry on oeis.org

1, 4, 9, 25, 10, 26, 34, 38, 30, 52, 74, 76, 82, 122, 90, 134, 146, 148, 114, 130, 194, 202, 206, 170, 226, 244, 186, 268, 292, 228, 290, 386, 388, 398, 404, 412, 370, 482, 366, 488, 434, 514, 430, 584, 518, 578, 614, 626, 450, 674, 462, 580, 610, 746, 558, 772
Offset: 1

Views

Author

Franz Vrabec, Jul 20 2007

Keywords

Examples

			a(5) = 10 is the unique solution to Cototient(x) = A131825(5) = 6.
		

Crossrefs

Programs

  • PARI
    lista(nn) = {my(c, r, v=vector(nn^2+2, i, i - eulerphi(i))); for(k=0, nn, c=0; for(i=1, k*k+2, if(k==v[i], r=i; c++)); if(c==1, print1(r, ", "))); } \\ Jinyuan Wang, Mar 22 2020

Extensions

More terms from Jinyuan Wang, Mar 22 2020