A077317 a(n) is the n-th prime == 1 (mod n).

2, 5, 19, 29, 71, 43, 211, 193, 271, 191, 661, 277, 937, 463, 691, 769, 1531, 613, 2357, 1021, 1723, 1409, 3313, 1609, 3701, 2029, 3187, 2437, 6961, 1741, 7193, 3617, 4951, 3877, 7001, 3169, 10657, 6271, 7879, 5521, 13613, 3823, 15137, 7349, 9091, 7499

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

Cf. A034694, A077316, A077318, A077319, A093871.

Sequence in context: A027714 A219178 A184868 * A092946 A090700 A227632

Adjacent sequences: A077314 A077315 A077316 * A077318 A077319 A077320

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