A261809 a(n) = n! - prime(n).

-1, -1, 1, 17, 109, 707, 5023, 40301, 362857, 3628771, 39916769, 479001563, 6227020759, 87178291157, 1307674367953, 20922789887947, 355687428095941, 6402373705727939, 121645100408831933, 2432902008176639929, 51090942171709439927, 1124000727777607679921

Offset

1,4

Links

G. C. Greubel, Table of n, a(n) for n = 1..85

Formula

a(n) = A000142(n) - A000040(n).

Example

For n=4, a(4) = 4! - prime(4) = 24 - 7 = 17.

Mathematica

Table[n! - Prime[n], {n, 1, 150}] (* G. C. Greubel, Sep 01 2015 *)

Prog

(PARI) vector(50, n, n!-prime(n))
(Magma) [Factorial(n)-NthPrime(n): n in [1..30]]; // Vincenzo Librandi, Sep 02 2015

Crossrefs

Cf. A000040, A000142, A121926.

Sequence in context: A013308 A297918 A298542 * A264723 A157099 A108649

Adjacent sequences: A261806 A261807 A261808 * A261810 A261811 A261812

Keyword

sign,easy

Author

Altug Alkan, Sep 01 2015

Status

approved