A075571 Rearrangement of odd primes such that sum of three successive terms is composite.

3, 5, 7, 13, 19, 17, 29, 11, 23, 31, 37, 43, 41, 59, 47, 53, 61, 71, 73, 101, 79, 67, 89, 97, 103, 109, 83, 107, 113, 131, 127, 137, 139, 149, 157, 163, 151, 167, 179, 173, 181, 191, 193, 197, 199, 227, 211, 229, 223, 233, 239, 241, 251, 257, 263, 269, 271

Offset

0,1

Links

Robert Israel, Table of n, a(n) for n = 0..10000

Maple

P:= select(isprime, [seq(i, i=7..1000, 2)]): nP:= nops(P):
R:= 3, 5: s:= 8:
for i from 3 to 100 do
  found:= false;
  for j from 1 to nP do
    if not isprime(s+P[j]) then
      found:= true; R:= R, P[j]; s:= R[-2]+P[j]; P:= subsop(j=NULL, P); nP:= nP-1; break
    fi;
  od;
  if not found then break fi;
od:
R; # Robert Israel, Jun 06 2025

Prog

(PARI) print1("3, 5, "); pr=vector(10000); v=vector(100); v[1]=3; v[2]=5; pr[3]=1; pr[5]=1; for(n=3, 100, forprime(p=3, 10000, if(!pr[p]&&!isprime(v[n-2]+v[n-1]+p), print1(p", "); v[n]=p; pr[p]=1; break)))

Crossrefs

Cf. A075572.

Sequence in context: A227531 A291867 A219674 * A077133 A164642 A247633

Adjacent sequences: A075568 A075569 A075570 * A075572 A075573 A075574

Keyword

nonn

Author

Amarnath Murthy, Sep 25 2002

Extensions

Corrected and extended by Ralf Stephan, Mar 27 2003

Status

approved