A129315 Where records occur in A127356.

1, 2, 3, 10, 13, 77, 92, 152, 294, 484, 517, 964, 1203, 2876, 14118, 34279, 81191, 103862, 115370, 195097, 334816, 347938, 2126572, 2787194, 3034023, 5707120, 16513290, 17861702, 19454321, 206814544, 500017558, 551865394, 716440254, 891826049, 1383516280

Offset

1,2

Links

Table of n, a(n) for n=1..35.

Example

The fifth record in A127356 is A129314(5) = 24 = A127356(13), hence a(5) = 13.

Prog

(Python)
from itertools import count, islice
from sympy import isprime, nextprime, prime
def agen():
    pn = 2; record = 1; yield 1
    for n in count(2):
        k, pn = 2, nextprime(pn)
        while not isprime(pn + k*k): k += 2
        if k > record: record = k; yield n
print(list(islice(agen(), 20))) # Michael S. Branicky, Nov 11 2022

Crossrefs

Cf. A127356, A129314 (records).

Sequence in context: A024852 A023856 A267008 * A171126 A299205 A268878

Adjacent sequences: A129312 A129313 A129314 * A129316 A129317 A129318

Keyword

nonn

Author

Klaus Brockhaus, Apr 09 2007

Extensions

a(27)-a(33) from Donovan Johnson, Dec 09 2008

a(34)-a(35) from Michael S. Branicky, Nov 11 2022

Status

approved