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A060424 Record-setting n's for the function q(n), the minimum prime q such that n(q+1)-1 is prime p (i.e., q(n) > q(j) for all 0 < j < n). 5

%I #17 Jan 26 2019 14:28:46

%S 1,3,7,13,31,51,101,146,311,1332,2213,6089,10382,11333,32003,83633,

%T 143822,176192,246314,386237,450644,1198748,2302457,5513867,9108629,

%U 11814707,16881479,18786623,24911213,28836722,34257764,196457309

%N Record-setting n's for the function q(n), the minimum prime q such that n(q+1)-1 is prime p (i.e., q(n) > q(j) for all 0 < j < n).

%H Amiram Eldar, <a href="/A060424/b060424.txt">Table of n, a(n) for n = 1..39</a>

%H Matthew M. Conroy, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL4/CONROY/conroy.html">A sequence related to a conjecture of Schinzel</a>, J. Integ. Seqs. Vol. 4 (2001), #01.1.7.

%e a(3)=7, since q(7)=5 and q(j) < 5 for 0 < j < 7.

%t q[n_] := Module[{p = 2}, While[! PrimeQ[n*(p+1)-1], p = NextPrime[p]]; p]; record = 0; a[0] = 0; a[n_] := a[n] = For[k = a[n-1]+1, True, k++, If[q[k] > record, record = q[k]; Print[k]; Return[k]]]; Table[a[n], {n, 1, 32}] (* _Jean-François Alcover_, Nov 18 2013 *)

%Y Cf. A060324. See A062252 and A062256 for the corresponding values of q and p.

%K nonn

%O 1,2

%A _Matthew Conroy_, Apr 10 2001

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Last modified September 17 09:48 EDT 2024. Contains 375987 sequences. (Running on oeis4.)