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A104311 Numbers n such that the coefficient of x^n in (x^3+x^2+x+1)^n is prime. 1
2, 4, 5, 8, 73, 649 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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.

LINKS

Table of n, a(n) for n=1..6.

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}]

CROSSREFS

Cf. A005725 (quadrinomial coefficients).

Sequence in context: A012973 A013154 A013129 * A200818 A021980 A303496

Adjacent sequences:  A104308 A104309 A104310 * A104312 A104313 A104314

KEYWORD

more,nonn

AUTHOR

T. D. Noe, Mar 01 2005

STATUS

approved

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Last modified December 5 12:24 EST 2021. Contains 349557 sequences. (Running on oeis4.)