OFFSET
1,1
COMMENTS
3313 is the smallest term such that 3313 +- 6 are both prime.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
71 is a term because it is the initial member of 5 consecutive primes {71, 73, 79, 83, 89} and (71 + 73 + 83 + 89)/4 = 79.
271 is a term because it is the initial member of 5 consecutive primes {271, 277, 281, 283, 293} and (271 + 277 + 283 + 293)/4 = 281.
MAPLE
MATHEMATICA
Select[Prime@ Range[1200], #[[3]] == Mean@ Delete[#, 3] &@ NestList[NextPrime, #, 4] &] (* Michael De Vlieger, Oct 09 2017 *)
PROG
(PARI) for(n=1, 1000, a=prime(n); b=prime(n+1); c=prime(n+2); d=prime(n+3); e=prime(n+4); if((a+b+d+e)/4==c, print1(a, ", ")));
(PARI) list(lim)=my(v=List(), p=2, q=3, r=5, s=7); forprime(t=11, lim, if(p+q+s+t==4*r, listput(v, p)); p=q; q=r; r=s; s=t); Vec(v) \\ Charles R Greathouse IV, Oct 09 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
K. D. Bajpai, Oct 08 2017
EXTENSIONS
Definiyion simplified by David A. Corneth, Oct 14 2017
STATUS
approved