OFFSET
1,1
COMMENTS
a(n) is the n-th prime in the arithmetic progression with first term 1 and common difference n.
Main diagonal of A077316.
LINKS
Zak Seidov, Table of n, a(n) for n = 1..1000
EXAMPLE
a(5) = 71, the fifth prime in the sequence 1, 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, ...
MAPLE
a:=proc(n) local N, B, j: N:=[seq(n*x+1, x=0..500)]: B:={}: for j from 1 to nops(N) do if isprime(N[j])=true then B:=B union {N[j]} else fi od: B[n]: end: seq(a(n), n=1..55); # Emeric Deutsch, Sep 03 2005
MATHEMATICA
Module[{nn=50, prs=Prime[Range[3000]]}, Join[{2}, Table[Select[prs, Mod[#, n] == 1&][[n]], {n, 2, nn}]]] (* Harvey P. Dale, Nov 13 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Nov 04 2002, Jul 23 2005 (submitted incorrectly on two separate occasions; each time it has had to be corrected)
EXTENSIONS
Edited, corrected and extended by Emeric Deutsch, Sep 03 2005 and by Franklin T. Adams-Watters, Aug 29 2006
Edited by N. J. A. Sloane, Aug 23 2008 at the suggestion of R. J. Mathar
STATUS
approved