

A175443


a(1)=2, a(n+1) = smallest prime > a(n) such that a(n+1)+a(n) is multiple of 5.


1



2, 3, 7, 13, 17, 23, 37, 43, 47, 53, 67, 73, 97, 103, 107, 113, 127, 163, 167, 173, 197, 223, 227, 233, 257, 263, 277, 283, 307, 313, 317, 353, 367, 373, 397, 433, 457, 463, 467, 503, 547, 563, 577, 593, 607, 613, 617, 643, 647, 653, 677, 683, 727, 733, 757
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OFFSET

1,1


COMMENTS

Lexicographically first subsequence of primes such that the sum of any two adjacent terms is a multiple of 5.  Charles R Greathouse IV, Apr 13 2015
For n >= 1, a(2*n) == 3 (mod 10) and a(2*n+1) == 7 (mod 10).  Robert Israel, Apr 13 2015


LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000


MAPLE

a[1]:= 2: a[2]:= 3:
for n from 2 to 99 do
for t from a[n]+ (2*a[n] mod 10) by 10 while not isprime(t) do od:
a[n+1]:= t;
od:
seq(a[n], n=1..100); # Robert Israel, Apr 13 2015


PROG

(PARI) list(lim)=my(v=List([2])); forprime(p=2, lim, if((v[#v]+p)%5, , listput(v, p))); Vec(v) \\ Charles R Greathouse IV, Apr 13 2015


CROSSREFS

Cf. A175451.
Sequence in context: A106306 A069104 A003631 * A032449 A129941 A159079
Adjacent sequences: A175440 A175441 A175442 * A175444 A175445 A175446


KEYWORD

nonn,easy


AUTHOR

Zak Seidov, May 28 2010


STATUS

approved



