A245723 a(n) = position of the first occurrence of n in A245714.

1, 3, 7, 19, 109, 509, 241, 317, 181, 1471, 2503, 2491, 7151, 11779, 3361, 2927, 1733, 5881, 15893, 16943, 11639, 31897, 25939, 12011, 17123, 6283, 10369, 63949, 8471, 125261, 64579, 117541, 21859, 58879, 44711, 216829, 64081, 67159, 73273, 181931, 139709

Offset: 1

Author

Vaclav Kotesovec, Jul 30 2014

Keywords

• nonn

Comments

Least m > 0 such that m+n! is the smallest prime of form m+k!. - Jens Kruse Andersen, Jul 30 2014

Examples

			a(2) = 3 since 3+2! is the smallest prime of the form 3+k!, and 3 is the least such number. While 1+2! is also prime, there is a smaller prime 1+1! in that case so a(2) is not 1. - _Jens Kruse Andersen_, Jul 30 2014
		

Links

• Vaclav Kotesovec and Jens Kruse Andersen, Table of n, a(n) for n = 1..200 (first 92 terms from Vaclav Kotesovec)

Crossrefs

Cf. A245714.

Programs

Mathematica

nmax=2000; Table[nn=1; k=0; While[k!=n && nnnn,k=0]; nn++]; If[nn==nmax,0,nn-1],{n,1,10}]

PARI

a(n)=for(k=1,n,if(ispseudoprime(n+k!),return(k)))
b(n)=for(k=1,10^6,if(a(k)==n,return(k)))
n=1;while(n<150,print1(b(n),", ");n++) \\ Derek Orr, Jul 30 2014