A239867 Where records occur in A239866.

1, 9, 91, 205, 362, 519, 634, 1202, 3075, 11620, 19197, 32786, 67401, 67947, 473326, 587793, 1215895, 1361552, 1998403, 2532886, 3039732, 5138070, 7058483, 9465973, 20128072, 76214152

Offset

1,2

Comments

The record values are 17, 40, 44, 58, 62, 68, 72, 106, 138, 144, 146, 190, 238, 240, 248, 258, 264, 290, 292, 340, 346, 348, 358, 378, 448, 452, ... - Amiram Eldar, Mar 31 2019

Links

Table of n, a(n) for n=1..26.

Example

It starts with a(1) = 1, that is for p_1 = 2 we have 17 (in A239866)
Then a(2) = 9 because for p_9 = 23 we have 40 > 17.
Again a(3) = 91 because for p_91 = 467 we have 44 > 40. 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, 70000}]; s (* Amiram Eldar, Mar 31 2019 *)

Crossrefs

Cf. A000040, A239864, A239865, A239866.

Sequence in context: A157584 A077334 A020243 * A217959 A014992 A015585

Adjacent sequences: A239864 A239865 A239866 * A239868 A239869 A239870

Keyword

nonn,more

Author

Paolo P. Lava, Mar 28 2014

Extensions

a(12)-a(26) from Amiram Eldar, Mar 31 2019

Status

approved