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