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).

1, 3, 7, 13, 31, 51, 101, 146, 311, 1332, 2213, 6089, 10382, 11333, 32003, 83633, 143822, 176192, 246314, 386237, 450644, 1198748, 2302457, 5513867, 9108629, 11814707, 16881479, 18786623, 24911213, 28836722, 34257764, 196457309

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..39

Matthew M. Conroy, A sequence related to a conjecture of Schinzel, J. Integ. Seqs. Vol. 4 (2001), #01.1.7.

Example

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

Mathematica

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 *)

Crossrefs

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

Sequence in context: A351318 A068679 A006978 * A119962 A333877 A220746

Adjacent sequences: A060421 A060422 A060423 * A060425 A060426 A060427

Keyword

nonn

Author

Matthew Conroy, Apr 10 2001

Status

approved