A186892 Nonprime numbers n such that the Stern polynomial B(n,x) is irreducible.

1, 25, 55, 65, 77, 91, 95, 115, 121, 125, 133, 143, 145, 161, 169, 175, 185, 203, 205, 209, 215, 235, 245, 247, 253, 265, 289, 295, 299, 301, 305, 319, 323, 329, 335, 343, 361, 377, 391, 395, 407, 415, 425, 427, 445, 451, 469, 473, 475, 485, 493, 505, 515, 517, 529, 533, 539, 545, 551, 559, 575, 581, 583, 623, 625

Offset: 1

Author

T. D. Noe, Feb 28 2011

Keywords

• nonn

Comments

See A186891 for all numbers n such that the Stern polynomial B(n,x) is irreducible.

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Programs

PARI

ps(n)=if(n<2,n,if(n%2,ps(n\2)+ps(n\2+1),'x*ps(n\2)))
is(n)=!isprime(n) && polisirreducible(ps(n)) \\ Charles R Greathouse IV, Apr 07 2015