0,3

This isomorphism can be used in most cases where mere A091203 would work, but in addition this preserves also the structures where we recurse on irreducible polynomial's A014580-index. E.g. we have: A091238(n) = A061775(a(n)). This is possible because the permutation contains an image of itself in its restriction to irreducible polynomials, i.e. a(n) = A049084(a(A014580(n))).

A. Karttunen, Scheme-program for computing this sequence.

Index entries for sequences operating on GF(2)[X]-polynomials

Index entries for sequences that are permutations of the natural numbers

a(0)=0, a(1)=1. For n's coding an irreducible polynomial, that is if n=A014580(i), we have a(n) = A000040(a(i)) and for reducible polynomials a(ir_i X ir_j X ...) = a(ir_i) * a(ir_j) * ..., where ir_i = A014580(i), X stands for carryless multiplication of GF(2)[X] polynomials (A048720) and * for the ordinary multiplication of integers (A004247).

Inverse: A091204.

Sequence in context: A091203 A106445 A106443 this_sequence A106447 A060866 A064478

Adjacent sequences: A091202 A091203 A091204 this_sequence A091206 A091207 A091208

nonn

Antti Karttunen (His-Firstname.His-Surname(AT)iki.fi), Jan 03 2004