cp's OEIS Frontend

A245820 Permutation of natural numbers induced when A245704 is restricted to {1} and binary codes for polynomials reducible over GF(2): a(1) = 1, a(n) = A062298(A245704(A091242(n-1))).

%I A245820 #15 Apr 01 2025 17:53:51
%S A245820 1,2,3,4,5,7,9,6,10,13,16,8,11,14,17,22,26,15,19,20,23,27,34,39,25,12,
%T A245820 29,31,35,40,50,24,56,37,21,43,46,38,51,57,70,48,36,78,53,33,61,18,65,
%U A245820 55,71,79,95,67,52,30,106,75,49,42,85,54,28,89,77,96,107,74,126,92,73,45,141,98,101,69,59,116,76,41,120,105
%N A245820 Permutation of natural numbers induced when A245704 is restricted to {1} and binary codes for polynomials reducible over GF(2): a(1) = 1, a(n) = A062298(A245704(A091242(n-1))).
%H A245820 Antti Karttunen, <a href="/A245820/b245820.txt">Table of n, a(n) for n = 1..10001</a>
%H A245820 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%F A245820 a(1) = 1, and for n > 1, a(n) = 1 + A245704(n-1).
%F A245820 a(1) = 1, and for n > 1, a(n) = A062298(A245704(A091242(n-1))). [Induced when A245704 is restricted to {1} and binary codes for polynomials reducible over GF(2)].
%F A245820 a(1) = 1, and for n > 1, a(n) = A036234(A245704(A014580(n-1))). [Induced also when A245703 is restricted to {1} and other binary codes for polynomials not reducible over GF(2)].
%F A245820 As a composition of related permutations:
%F A245820 a(n) = A245816(A245813(n)).
%o A245820 (PARI) \\ The rest of code can be found in A245704.
%o A245820 A245820(n) = if(1==n, 1, 1 + A245704(n-1));
%o A245820 (Scheme)
%o A245820 (define (A245820 n) (if (<= n 1) n (+ 1 (A245704 (- n 1)))))
%o A245820 (Scheme)
%o A245820 (define (A245820 n) (if (<= n 1) n (A062298 (A245704 (A091242 (- n 1))))))
%o A245820 (Scheme)
%o A245820 (define (A245820 n) (if (<= n 1) n (A036234 (A245704 (A014580 (- n 1))))))
%Y A245820 Inverse: A245819.
%Y A245820 Related permutations: A245704, A245813, A245816.
%Y A245820 Cf. A014580, A036234, A062298, A091242.
%K A245820 nonn
%O A245820 1,2
%A A245820 _Antti Karttunen_, Aug 16 2014