OFFSET
1,1
COMMENTS
It is a plausible conjecture that a(n) always exists. - N. J. A. Sloane, Jul 21 2018
EXAMPLE
a(1) = A058620(1) = 7;
a(2) = 89 because (97 - 89)/4 = 8/4 = 2, a prime; etc.
MATHEMATICA
t[_] := 0; p = 3; q = 5; While[p < 10000000, d = (q - p)/2; If[ t[d] == 0, t[d] = p]; p = q; q = NextPrime@ q]; t@# & /@ (2 Range@ 30)
PROG
(PARI) a(n) = {my(p = 2); forprime(q=3, , my(d = q-p); if (d/(2*n)==2, return (p)); p = q; ); } \\ Michel Marcus, Jun 22 2018; corrected Jun 15 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov and Robert G. Wilson v, Jun 19 2018
EXTENSIONS
Name corrected by Jinyuan Wang, Jun 15 2022
STATUS
approved