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A061410 Numbers k such that m*2^k+1 is not prime for all coefficients m in the range 0<=m<=k. 6
9, 10, 22, 31, 86, 99, 100, 101, 113, 114, 115, 130, 135, 136, 149, 154, 169, 217, 218, 223, 224, 283, 301, 309, 358, 383, 384, 422, 423, 424, 425, 426, 449, 457, 473, 495, 505, 506, 541, 542, 548, 549, 564, 571, 572, 573, 628, 668, 670, 681, 682, 683, 713 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..285

MAPLE

filter:= n -> andmap(not isprime, [seq(m*2^n+1, m=1..n)]):

select(filter, [$1..1000]); # Robert Israel, Dec 10 2017

MATHEMATICA

okQ[n_] := AllTrue[2^n Range[n] + 1, CompositeQ];

Select[Range[1000], okQ] (* Jean-Fran├žois Alcover, Mar 25 2019 *)

PROG

(PARI) isok(n) = {for (m=0, n, if (isprime(m*2^n+1), return (0)); ); return (1); } \\ Michel Marcus, Dec 11 2017

CROSSREFS

Cf. A061411, A061412, A061413, A061414, A061415.

Sequence in context: A260184 A109463 A326523 * A309485 A228378 A326464

Adjacent sequences:  A061407 A061408 A061409 * A061411 A061412 A061413

KEYWORD

nonn

AUTHOR

Patrick De Geest, May 15 2001

STATUS

approved

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Last modified October 20 02:18 EDT 2019. Contains 328244 sequences. (Running on oeis4.)