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.

A104492 Cube excess of the n-th prime.

Original entry on oeis.org

1, 2, 4, 6, 3, 5, 9, 11, 15, 2, 4, 10, 14, 16, 20, 26, 32, 34, 3, 7, 9, 15, 19, 25, 33, 37, 39, 43, 45, 49, 2, 6, 12, 14, 24, 26, 32, 38, 42, 48, 54, 56, 66, 68, 72, 74, 86, 7, 11, 13, 17, 23, 25, 35, 41, 47, 53, 55, 61, 65, 67, 77, 91, 95, 97, 101, 115, 121, 4, 6, 10, 16, 24, 30
Offset: 1

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Author

Jonathan Vos Post, Mar 10 2005

Keywords

Examples

			a(48) = 7 because the 48th prime is 223 and 223 - 6^3 = 7, while 223 - 7^3 = -120.
		

Crossrefs

Programs

Formula

a(n) = A055400(A000040(n)).
a(n) = prime(n) - floor(prime(n)^(1/3))^3. - Jon E. Schoenfield, Jan 17 2015

A104491 Prime numbers n for which the square excess of the n-th prime is prime.

Original entry on oeis.org

2, 5, 13, 19, 23, 37, 67, 71, 83, 107, 109, 113, 139, 157, 173, 199, 271
Offset: 1

Views

Author

Jonathan Vos Post, Mar 10 2005

Keywords

Examples

			199 is an element of this sequence because 199 is prime and the 199th prime is 1217 and 1217 - 34^2 = 61 and 61 is prime, while 1217 - 35^2 = -8.
		

Crossrefs

Formula

n such that A102821(n) is prime. n such that A053186(A000040(n)) is an element of A000040.

A104493 Numbers n for which the cube excess of the n-th prime is prime.

Original entry on oeis.org

2, 5, 6, 8, 10, 19, 20, 23, 26, 28, 31, 48, 49, 50, 51, 52, 55, 56, 57, 59, 61, 65, 66, 99, 100, 105, 110, 112, 114, 117, 121, 125, 127, 170, 171, 173, 178, 184, 185, 186, 190, 192, 194, 196, 200, 201, 206, 208, 214, 270, 271, 272, 274, 277, 278, 279, 280, 282
Offset: 1

Views

Author

Jonathan Vos Post, Mar 19 2005

Keywords

Examples

			99 is an element of this sequence because the 99th prime is 523, 523 - 8^3 = 523-512 = 11 and 11 is prime. 100 is in this sequence because the 100th prime is 541 and 541-8^3 = 29, which is prime.
		

Crossrefs

Programs

  • Mathematica
    f[n_] := Block[{k = 1, p = Prime[n]}, While[k^3 < p, k++ ]; p - (k - 1)^3]; Select[ Range[ 284], PrimeQ[ f[ # ]] &] (* Robert G. Wilson v, Mar 19 2005 *)

Formula

n such that A055400(A000040(n)) is an element of A000040. n such that A104492(n) is prime.

Extensions

More terms from Robert G. Wilson v, Mar 19 2005
Showing 1-3 of 3 results.