login
A239865
Where records occur in A239864.
3
1, 2, 44, 51, 111, 300, 357, 3603, 3779, 5326, 5372, 30817, 117498, 151450, 166877, 545114, 5941303, 14726486, 16436691, 17402909, 32947955, 77092704, 202485484, 328878332, 383238249, 435910049
OFFSET
1,2
COMMENTS
The record values are 1, 16, 22, 40, 54, 64, 90, 94, 112, 180, 184, 192, 202, 204, 256, 368, 388, 390, 418, 460, 472, 500, ... - Amiram Eldar, Mar 31 2019
EXAMPLE
It starts with a(1) = 1, that is for p_1 = 2 we have 1 in A239864.
Then a(2) = 2 because for p_2 = 3 we have 16 > 1.
Again a(3) = 44 because for p_44 = 193 we have 22 > 16. Etc.
MAPLE
P:=proc(q) local a, b, c, d, n, t; t:=0;
for n from 1 to q do a:=1; b:=ithprime(n); c:=b; d:=b+1;
while not isprime(d) do a:=a+1; c:=nextprime(c); d:=d+c; od;
if a>t then t:=a; print(n); fi; od; end: P(10^6);
MATHEMATICA
a[n_] := Module[{s = 1, k = 0, p = Prime[n]}, While[!PrimeQ[s], s += p; p = NextPrime[p]; k++]; k]; am = 0; s={}; Do[a1 = a[n]; If[a1 > am, am = a1; AppendTo[s, n]], {n, 1, 120000}]; s (* Amiram Eldar, Mar 31 2019 *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Paolo P. Lava, Mar 28 2014
EXTENSIONS
a(13)-a(22) from Amiram Eldar, Mar 31 2019
a(23)-a(26) from Michael S. Branicky, Feb 10 2026
STATUS
approved