A100859 Beginning with 3, increasing primes such that no two adjacent terms are congruent mod 4.

3, 5, 7, 13, 19, 29, 31, 37, 43, 53, 59, 61, 67, 73, 79, 89, 103, 109, 127, 137, 139, 149, 151, 157, 163, 173, 179, 181, 191, 193, 199, 229, 239, 241, 251, 257, 263, 269, 271, 277, 283, 293, 307, 313, 331, 337, 347, 349, 359, 373, 379, 389, 419, 421, 431, 433

Offset

1,1

Links

Table of n, a(n) for n=1..56.

Formula

a(2n-1)==3 (mod 4) and a(2n)==1 (mod 4).

Mathematica

a[1] = 3; a[n_] := a[n] = Block[{k}, k = a[n - 1] + 2; While[ ! PrimeQ[k], k = k + 4]; Return[k]; ]; Table[a[n], {n, 100}]

Crossrefs

Sequence in context: A338567 A340339 A126108 * A336369 A111703 A184248

Adjacent sequences: A100856 A100857 A100858 * A100860 A100861 A100862

Keyword

nonn,easy

Author

Giovanni Teofilatto, Jan 13 2005

Extensions

Edited and extended by Ray Chandler, Jan 19 2005

Status

approved