A077321 Rearrange primes so as to form a triangle in which n-th row contains the n smallest primes == 1 (mod n) which have not occurred earlier.

2, 3, 5, 7, 13, 19, 17, 29, 37, 41, 11, 31, 61, 71, 101, 43, 67, 73, 79, 97, 103, 113, 127, 197, 211, 239, 281, 337, 89, 137, 193, 233, 241, 257, 313, 353, 109, 163, 181, 199, 271, 307, 379, 397, 433, 131, 151, 191, 251, 311, 331, 401, 421, 431, 461, 23, 419, 463, 617

Offset

1,1

Links

Ivan Neretin, Table of n, a(n) for n = 1..5050

Example

Triangle begins:
2
3 5
7 13 19
17 29 37 41
11 31 61 71 101
...

Maple

A077321 := proc(nmax) local n, a, i, p; a := []; n :=1; while nops(a) < nmax do for i from 1 to n do p := 2; while ( p in a ) or (p-1) mod n <> 0 do p := nextprime(p); od; a := [op(a), p]; od; n := n+1; od; RETURN(a); end: A077321(100); # R. J. Mathar, Feb 03 2007

Mathematica

A077321[nmax_] := Module[{n = 1, a = {}, i, p}, While[ Length[a] < nmax, For[i = 1, i <= n, i++,  p = 2; While[ MemberQ[a, p] || Mod[p - 1, n] != 0, p = NextPrime[p]]; a = Append[a, p]]; n = n + 1]; Return[a]];
A077321[100] (* Jean-François Alcover, May 30 2023, after R. J. Mathar *)

Crossrefs

Cf. A077322, A077323, A077324, A077325.

Cf. A100787, A100788, A100789, A100790.

Sequence in context: A077316 A082011 A101044 * A216437 A165666 A154579

Adjacent sequences: A077318 A077319 A077320 * A077322 A077323 A077324

Keyword

nonn,tabl

Author

Amarnath Murthy, Nov 04 2002, Nov 30 2004

Extensions

More terms from Ray Chandler, Dec 10 2004

Edited by N. J. A. Sloane, Sep 14 2008 at the suggestion of R. J. Mathar

Status

approved