cp's OEIS Frontend

A239800 First appearance of n in A016014, or 0 if n never occurs.

%I A239800 #19 Oct 05 2021 12:46:07
%S A239800 1,4,12,42,19,59,92,196,184,159,334,227,317,415,256,521,514,796,734,
%T A239800 1861,1691,1997,2053,706,5006,5731,3814,2348,5641,1466,19016,5542,
%U A239800 26815,8762,18637,5794,31667,5227,17054,35246,51148,5207,59537,75862,54737,117899,58603,81313,30332,100042,205471,113018,102307,21209,63971,321994,62809,648512
%N A239800 First appearance of n in A016014, or 0 if n never occurs.
%C A239800 Conjecture: a(n) > 0 for all n. - _Jianing Song_, Mar 09 2021
%H A239800 Zak Seidov, <a href="/A239800/b239800.txt">Table of n, a(n) for n = 1..100</a>
%F A239800 A016014(a(n)) = n.
%p A239800 isA239800 := proc(n, m) local k;
%p A239800 for k from 1 to n-1 while not isprime(2*m*k + 1) do od;
%p A239800 if k < n then false else isprime(2*m*n + 1) fi end:
%p A239800 A239800 := proc(n, SearchLimit) local k;
%p A239800 for k from 1 to SearchLimit do if isA239800(n, k) then return k fi od;
%p A239800 error "Search limit reached!" end:
%p A239800 A239800List := (ListLength, SearchLimit) ->
%p A239800 map(n -> A239800(n, SearchLimit), [$1..ListLength]):
%p A239800 A239800List(32, 65537); # _Peter Luschny_, Oct 05 2021
%Y A239800 Cf. A016014, A239746, A239727.
%K A239800 nonn
%O A239800 1,2
%A A239800 _Zak Seidov_, Mar 27 2014
%E A239800 Escape clause added by _Jianing Song_, Mar 09 2021