A381020 a(n) = A381018(100*n).

30, 45, 60, 75, 92, 106, 119, 133, 141, 157, 170, 177, 185, 204, 224, 236, 245, 260, 275, 292, 305, 318, 330, 342, 359, 371, 382, 390, 405, 419, 430, 444, 457, 472, 490, 507, 524, 535, 550, 561, 570, 583, 593, 604, 611, 621, 627, 638, 647, 659, 670, 679, 683, 697

Offset

1,1

Links

Table of n, a(n) for n=1..54.

Thomas Ehrenborg, Gauss Circle Primes, arXiv:2502.06804 [math.GM], 2025. See Table 2 p. 4.

Prog

(Python)
from math import isqrt
from sympy import isprime
def A381020(n): return sum(1 for m in range(1, 100*n+1) if isprime(1+(sum(isqrt(k*((m<<1)-k)) for k in range(1, m+1))<<2))) # Chai Wah Wu, Feb 13 2025

Crossrefs

Cf. A028505, A381018.

Sequence in context: A062385 A164803 A152569 * A114944 A075290 A281919

Adjacent sequences: A381017 A381018 A381019 * A381021 A381022 A381023

Keyword

nonn

Author

Michel Marcus, Feb 12 2025

Extensions

More terms from Jinyuan Wang, Feb 13 2025

Status

approved