A071150 Primes p such that the sum of all odd primes <= p is also a prime.
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
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
Links
- R. J. Mathar, Table of n, a(n) for n = 1..5908
Programs
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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
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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 *)
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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