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.

Showing 1-3 of 3 results.

A243896 a(n) = prime(n^2+1).

Original entry on oeis.org

2, 3, 11, 29, 59, 101, 157, 229, 313, 421, 547, 673, 829, 1013, 1201, 1429, 1621, 1889, 2153, 2441, 2749, 3089, 3463, 3821, 4217, 4639, 5059, 5521, 6011, 6491, 7001, 7577, 8167, 8741, 9343, 9941, 10631, 11329, 12071, 12757, 13513, 14341, 15107, 15881
Offset: 0

Views

Author

Freimut Marschner, Jun 17 2014

Keywords

Comments

For n>1, the numbers prime(n^2-1), prime(n^2) and prime(n^2+1), that is, A243895(n), A001248(n) and a(n), constitute a triple of successive prime numbers.

Examples

			n = 4, n^2 = 16, n^2 + 1 = 17, prime(17) = 59.
		

Crossrefs

Cf. A000290 (squares n^2), A000040 (prime(n)), A001248 (prime(n)^2). A011757 (prime(n^2)), A055875 (prime(n^3)), A096327 (prime((prime(n)^2))), A096328 (prime(prime(n)^3)), A038580 (prime(prime(prime(n)))).

Programs

  • Mathematica
    Table[Prime[n^2+1],{n,0,50}] (* Harvey P. Dale, Dec 25 2022 *)

Formula

a(n) = prime(n^2 + 1) = prime(A000290(n) + 1) = prime(A002522(n)).

A243892 a(n) = prime(k) with k = n^2 + prime(n)^2.

Original entry on oeis.org

11, 41, 139, 313, 839, 1259, 2273, 2953, 4493, 7417, 8689, 12659, 15881, 17837, 21683, 28097, 35401, 38321, 46993, 53353, 56909, 67499, 75277, 87539, 105167, 115061, 120431, 130817, 136559, 147881, 189127, 202493
Offset: 1

Views

Author

Freimut Marschner, Jun 14 2014

Keywords

Examples

			n = 1, prime(1^2+prime(1)^2) = prime(1 + 2^2) = prime(5) = 11.
n = 2, prime(2^2+prime(2)^2) = prime(4 + 3^2) = prime(13) = 41.
		

Crossrefs

Cf. A000290 (squares n^2), A000040 (prime(n)), A001248 (prime(n)^2), A106587 (n^2 + prime(n)^2).
Also A011757 is prime(n^2), A096327 is prime(prime(n)^2).

Formula

a(n) = prime((n^2 + prime(n)^2)) = prime(A106587(n)).

A243895 a(n) = prime(n^2-1).

Original entry on oeis.org

5, 19, 47, 89, 149, 223, 307, 409, 523, 659, 823, 997, 1187, 1423, 1613, 1877, 2141, 2423, 2731, 3079, 3457, 3797, 4201, 4621, 5039, 5507, 5987, 6473, 6991, 7561, 8147, 8731, 9337, 9929, 10613, 11317, 12043, 12739, 13487, 14323, 15091, 15859, 16741
Offset: 2

Views

Author

Freimut Marschner, Jun 17 2014

Keywords

Comments

The prime numbers prime(k-1), prime(k) = A001248 and prime(k+1) = A243896 with k = n^2 are building a triple of successive prime numbers. Remark: prime(n^2-1) is not defined for n=1.

Examples

			n = 3, n^2 = 9, n^2-1 = 8, prime(8) = 19.
		

Crossrefs

Cf. A000290 (squares n^2), A000040 (prime(n)), A001248 (prime(n)^2), A011757 (prime(n^2)), A055875 (prime(n^3)), A096327 (prime((prime(n)^2))), A096328 (prime(prime(n)^3)), A038580 (prime(prime(prime(n)))).

Programs

  • Mathematica
    Table[Prime[n^2-1],{n,2,50}] (* Harvey P. Dale, Jul 16 2025 *)

Formula

a(n) = prime(n^2-1) = prime(A000290(n) - 1) = prime(A005563(n-1)).
Showing 1-3 of 3 results.