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A239800 First appearance of n in A016014, or 0 if n never occurs. 2

%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

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Last modified April 20 02:14 EDT 2024. Contains 371798 sequences. (Running on oeis4.)