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 1-2 of 2 results.

A104314 Prime coefficient of x^(2*k) in (x^4 + x^3 + x^2 + x + 1)^k for k in A104313.

Original entry on oeis.org

5, 19, 1974442362935339179, 47705925773278538281, 234692178470218983001
Offset: 1

Views

Author

T. D. Noe, Mar 01 2005

Keywords

Comments

a(6) > A005191(195315), if it exists. See A104313 for more information. - Jinyuan Wang, Jul 26 2021

Crossrefs

Cf. A005191 (pentanomial coefficients), A104312 (nontrivial prime quadrinomial coefficients), A104313.

Programs

  • Mathematica
    f=1; Do[f=Expand[f*(x^4+x^3+x^2+x+1)]; s=Coefficient[f, x, 2n]; If[PrimeQ[s], Print[{n, s}]], {n, 100}]

A104311 Numbers n such that the coefficient of x^n in (x^3+x^2+x+1)^n is prime.

Original entry on oeis.org

2, 4, 5, 8, 73, 649
Offset: 1

Views

Author

T. D. Noe, Mar 01 2005

Keywords

Comments

n such that A005725(n) is prime. No other n<16000. The primes are in A104312. Only coefficients of the x, x^n, x^(2n) and x^(3n-1) terms can be prime; the coefficients of x and x^(3n-1) terms are prime whenever n is prime.
Any further terms are > 500000. - Lucas A. Brown, Oct 04 2024

Crossrefs

Cf. A005725 (quadrinomial coefficients).

Programs

  • Mathematica
    f=1; Do[f=Expand[f*(x^3+x^2+x+1)]; s=Coefficient[f, x, n]; If[PrimeQ[s], Print[{n, s}]], {n, 1000}]
Showing 1-2 of 2 results.