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

1, 4, 12, 42, 19, 59, 92, 196, 184, 159, 334, 227, 317, 415, 256, 521, 514, 796, 734, 1861, 1691, 1997, 2053, 706, 5006, 5731, 3814, 2348, 5641, 1466, 19016, 5542, 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

Offset: 1

Author

Zak Seidov, Mar 27 2014

Keywords

• nonn

Comments

Conjecture: a(n) > 0 for all n. - Jianing Song, Mar 09 2021

Links

• Zak Seidov, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A016014, A239746, A239727.

Programs

Maple

isA239800 := proc(n, m) local k;
for k from 1 to n-1 while not isprime(2*m*k + 1) do od;
if k < n then false else isprime(2*m*n + 1) fi end:
A239800 := proc(n, SearchLimit) local k;
for k from 1 to SearchLimit do if isA239800(n, k) then return k fi od;
error "Search limit reached!" end:
A239800List := (ListLength, SearchLimit) ->
map(n -> A239800(n, SearchLimit), [$1..ListLength]):
A239800List(32, 65537); # Peter Luschny, Oct 05 2021

Formula

A016014(a(n)) = n.

Extensions

Escape clause added by Jianing Song, Mar 09 2021