A088584 Primes of the form n*x^n + (n-1)*x^(n-1) + . . . + x + 1 for x=3.

103, 312088729, 9955641160957, 163142317702973500798039087, 327058383882861814163660125754017, 67973813526967723994124686175157751059, 545249446055539622797498212423248888694512551610580463

Offset

1,1

Comments

Sum of reciprocals = 0.009708741068395080316898549713.. Are these primes infinite?

The next term (a(8)) has 148 digits. - Harvey P. Dale, Dec 15 2018

Links

Table of n, a(n) for n=1..7.

Example

3*3^3 + 2*3^2 + 3 + 1 = 103.

Mathematica

Select[Accumulate[Join[{1}, Table[n*3^n, {n, 200}]]], PrimeQ] (* Harvey P. Dale, Dec 15 2018 *)

Prog

(PARI) trajpolyp(n1, k) = { s=0; for(x1=0, n1, y1 = polypn2(k, x1); if(isprime(y1), print1(y1", "); s+=1.0/y1; ) ); print(); print(s) } polypn2(n, p) = { x=n; y=1; for(m=0, p, y=y+m*x^m; ); return(y) }

Crossrefs

Sequence in context: A245495 A097726 A262273 * A238490 A097014 A106297

Adjacent sequences: A088581 A088582 A088583 * A088585 A088586 A088587

Keyword

nonn

Author

Cino Hilliard, Nov 20 2003

Extensions

More terms from Harvey P. Dale, Dec 15 2018

Status

approved