cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A071150 Primes p such that the sum of all odd primes <= p is also a prime.

Original entry on oeis.org

3, 29, 53, 61, 251, 263, 293, 317, 359, 383, 503, 641, 647, 787, 821, 827, 911, 1097, 1163, 1249, 1583, 1759, 1783, 1861, 1907, 2017, 2287, 2297, 2593, 2819, 2837, 2861, 3041, 3079, 3181, 3461, 3541, 3557, 3643, 3779, 4259, 4409, 4457, 4597, 4691, 4729, 4789
Offset: 1

Views

Author

Labos Elemer, May 13 2002

Keywords

Examples

			29 is a prime and 3 + 5 + 7 + 11 + 13 + 17 + 19 + 23 + 29 = 127 (also a prime), so 29 is a term. - _Jon E. Schoenfield_, Mar 29 2021
		

Crossrefs

Programs

  • Maple
    SoddP := proc(n)
        option remember;
        if n <= 2 then
            0;
        elif isprime(n) then
            procname(n-1)+n;
        else
            procname(n-1);
        fi ;
    end proc:
    isA071150 := proc(n)
        if isprime(n) and isprime(SoddP(n)) then
            true;
        else
            false;
        end if;
    end proc:
    n := 1 ;
    for i from 3 by 2 do
        if isA071150(i) then
            printf("%d %d\n",n,i) ;
            n := n+1 ;
        end if;
    end do: # R. J. Mathar, Feb 13 2015
  • Mathematica
    Function[s, Select[Array[Take[s, #] &, Length@ s], PrimeQ@ Total@ # &][[All, -1]]]@ Prime@ Range[2, 640] (* Michael De Vlieger, Jul 18 2017 *)
    Module[{nn=650,pr},pr=Prime[Range[2,nn]];Table[If[PrimeQ[Total[Take[ pr, n]]], pr[[n]],Nothing],{n,nn-1}]] (* Harvey P. Dale, May 12 2018 *)
  • Python
    from sympy import isprime, nextprime
    def aupto(limit):
      p, s, alst = 3, 3, []
      while p <= limit:
        if isprime(s): alst.append(p)
        p = nextprime(p)
        s += p
      return alst
    print(aupto(4789)) # Michael S. Branicky, Mar 29 2021