A339900 - OEIS

%I #16 Apr 25 2022 14:01:46

%S 3,5,7,41,11,13,19,17,23,29,31,73,43,37,47,97,59,53,67,89,71,61,79,

%T 113,83,101,103,137,107,109,127,193,131,149,139,233,151,157,163,241,

%U 167,173,179,281,191,181,199,353,211,197,223,313,227,229,239,337,251,269,263,409,271,277,283,641,307,293,311,457,331

%N Lexicographically earliest permutation of odd primes such that A007814(a(n)-1) = 1+A007814(n), where A007814 gives the 2-adic valuation of n.

%H Antti Karttunen, <a href="/A339900/b339900.txt">Table of n, a(n) for n = 1..20000</a>

%o (PARI) A339900(n) = { my(lev=1+valuation(n,2), k=(1+(n>>(lev-1)))/2); forprime(p=3,,if(valuation(p-1,2)==lev, k--; if(!k, return(p)))); };

%Y Cf. A001511, A007814, A065091.

%Y Cf. A002145 (odd bisection), A007521 (quadrisection starting from 5), A105126, A105127, A105128, A105129, A105130, A105131, A105132.

%Y Cf. also A108546, A111745.

%K nonn,look

%O 1,1

%A _Antti Karttunen_, Dec 25 2020