A154497 a(n) is the least prime > a(n-1) such that a(n-2) + a(n-1) + a(n) is prime, with a(1)=3, a(2)=11.

3, 11, 17, 19, 23, 29, 31, 37, 41, 53, 73, 97, 101, 109, 127, 131, 139, 149, 151, 157, 179, 211, 223, 227, 233, 241, 269, 277, 281, 349, 353, 359, 379, 433, 467, 499, 521, 523, 557, 577, 587, 613, 631, 743, 757, 769, 821, 827, 829, 883, 947, 967, 983, 1013, 1087

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

3+11+17 = 31, 11+17+19 = 47, 17+19+23 = 59, ...

Maple

A[1]:= 3: A[2]:= 11:
for i from 3 to 100 do
  p:= A[i-1];
  do
    p:= nextprime(p);
    if isprime(A[i-2]+A[i-1]+p) then
       A[i]:= p; break
    fi
  od
od:
seq(A[i], i=1..100); # Robert Israel, Jan 17 2023

Mathematica

a=3; b=11; lst={a, b}; Do[c=Prime[n]; p=a+b+c; If[PrimeQ[p], AppendTo[lst, c]; a=b; b=c], {n, 5, 6!}]; lst

Crossrefs

Cf. A154484, A154485, A154486, A154487, A154488, A154493, A154494, A154495, A154496, A062391.

Sequence in context: A216911 A356074 A351051 * A322171 A038946 A095280

Adjacent sequences: A154494 A154495 A154496 * A154498 A154499 A154500

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Jan 10 2009

Extensions

NAME adapted to offset by R. J. Mathar, Jun 19 2021

Name corrected by Robert Israel, Jan 17 2023

Status

approved