1,1

This sequence is probably not complete. It contains those members of A076336 that are prime.

Baillie, R., Cormack, G., Williams, H. C.; The Problem of Sierpinski Concerning k 2^n+1, Mathematics of Computation, Vol. 37, No. 155. (July 1981), pp. 229-231. Corrigenda; Mathematics of Computation, Vol. 39, No. 159. (July 1982), p. 308.

Keller, Wilfred; Factors of Fermat Numbers and Large Primes of the Form, Mathematics of Computation, Vol. 41, No. 164. (October 1983), pp. 661-673.

Sierpinski, W.; Sur un probleme concernant les nombres k 2^n+1, Elem. d. Math. 15, pp. 73-74, 1960.

Mersenne Forum, The Prime Sierpinski Problem.

Seventeen or Bust, A Distributed Attack on the Sierpinski problem

As 271129 is the first known prime value of k for which k 2^n+1 is composite for all positive integers n, a(1)= 271129.

Cf. A057192, A076336.

Sequence in context: A124946 A139028 A075467 this_sequence A013998 A114663 A128479

Adjacent sequences: A137712 A137713 A137714 this_sequence A137716 A137717 A137718

hard,nonn

Ant King (mathstutoring(AT)ntlworld.com), Feb 09 2008