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.

A352912 Irregular triangle read by rows: row n (n>=1) lists the primes of the form prime(n) + k! for k >= 0.

Original entry on oeis.org

3, 3, 5, 7, 11, 29, 13, 31, 127, 727, 13, 17, 131, 5051, 3628811, 19, 37, 733, 19, 23, 41, 137, 362897, 39916817, 43, 139, 739, 5059, 3628819, 39916819, 87178291219, 29, 47, 743, 40343, 362903, 20922789888023, 31, 53, 149, 39916829, 479001629, 2432902008176640029, 37, 151, 751, 40351, 362911, 39916831, 355687428096031, 51090942171709440031, 1124000727777607680031
Offset: 1

Views

Author

Editors of OEIS, based on a suggestion from Hemjyoti Nath, Apr 16 2022

Keywords

Examples

			The initial rows, prefixed by prime(n), are:
[2]: 3, 3,
[3]: 5,
[5]: 7, 11, 29,
[7]: 13, 31, 127, 727,
[11]: 13, 17, 131, 5051, 3628811,
[13]: 19, 37, 733,
[17]: 19, 23, 41, 137, 362897, 39916817,
[19]: 43, 139, 739, 5059, 3628819, 39916819, 87178291219,
[23]: 29, 47, 743, 40343, 362903, 20922789888023,
[29]: 31, 53, 149, 39916829, 479001629, 2432902008176640029,
[31]: 37, 151, 751, 40351, 362911, 39916831, 355687428096031, 51090942171709440031, 1124000727777607680031,
[37]: 43, 61, 157, 757, 5077, 40357, 39916837, 6402373705728037, 2432902008176640037, 51090942171709440037, 8683317618811886495518194401280000037,
...
		

Crossrefs

Cf. A352913 (last term in each row), A082470 (lengths of rows).

Programs

  • PARI
    forprime(p=2,59,print1([p],": ");for(k=0,p,if(ispseudoprime(p+k!),print1(p+k!,", ")));print())
    
  • Python
    from sympy import isprime, prime
    from itertools import count, islice
    def agen(): # generator of terms
        for n in count(1):
            pn, fk = prime(n), 1
            for k in range(1, pn+1):
                if isprime(pn + fk): yield pn + fk
                fk *= k
    print(list(islice(agen(), 51))) # Michael S. Branicky, Apr 16 2022