cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

Original entry on oeis.org

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

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Author

Michel Marcus, Feb 12 2025

Keywords

Crossrefs

Programs

  • 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

Extensions

More terms from Jinyuan Wang, Feb 13 2025