A245482 - OEIS

A245482

Semiprimes of the form m^6 - m^5 + m^4 - m^3 + m^2 - m + 1.

3277, 13021, 102943, 233017, 478297, 2756293, 44693587, 465273397, 705483871, 859769191, 2117950381, 3996097561, 8123248981, 10554648343, 11980986577, 15318627451, 21753909997, 30299909641, 33705129193, 37423460467, 41477524747, 45891147541, 97434620557, 106376475037

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

All the terms in this sequence are odd semiprimes.

Primes of this form are at A245427.

LINKS

K. D. Bajpai, Table of n, a(n) for n = 1..11040

EXAMPLE

m = 4: m^6 - m^5 + m^4 - m^3 + m^2 - m + 1 = 3277 = 29 * 113, which is semiprime and appears in the sequence.

m = 5: m^6 - m^5 + m^4 - m^3 + m^2 - m + 1 = 13021 = 29 * 449, which is semiprime and appears in the sequence.

MATHEMATICA

A245482 = {}; k = n^6 - n^5 + n^4 - n^3 + n^2 - n + 1; Do[If[PrimeOmega[k] == 2, AppendTo[A245482, k]], {n, 100}]; A245482

PROG

(PARI) for(n=1, 100, s=sum(i=0, 6, (-n)^i); if(bigomega(s)==2, print1(s, ", "))) \\ Derek Orr, Jul 28 2014

CROSSREFS

Cf. A001358, A162861, A245393, A245427.

Sequence in context: A307809 A141629 A116460 * A356638 A244626 A270204

Adjacent sequences: A245479 A245480 A245481 * A245483 A245484 A245485

KEYWORD

nonn

AUTHOR

K. D. Bajpai, Jul 23 2014

STATUS

approved