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A065381 Primes not of the form p + 2^k, p prime and k >= 0. 8
2, 127, 149, 251, 331, 337, 373, 509, 599, 701, 757, 809, 877, 907, 977, 997, 1019, 1087, 1259, 1549, 1597, 1619, 1657, 1759, 1777, 1783, 1867, 1973, 2203, 2213, 2293, 2377, 2503, 2579, 2683, 2789, 2843, 2879, 2909, 2999, 3119, 3163, 3181, 3187, 3299 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

LINKS

T. D. Noe, Table of n, a(n) for n=1..1000

P. Pollack, Not Always Buried Deep: Selections from Analytic and Combinatorial Number Theory, p. 193, ex. 5.1.6, p. 216ff. [?Broken link]

P. Pollack, Not Always Buried Deep: Selections from Analytic and Combinatorial Number Theory, p. 193, ex. 5.1.6, p. 216ff.

Lei Zhou, Between 2^n and primes.

FORMULA

A078687(A049084(a(n))) = 0; subsequence of A118958. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 07 2006

EXAMPLE

127 is a prime, 127-2^0 through 127-2^6 are all nonprimes.

MATHEMATICA

fQ[n_] := Block[{k = Floor[ Log[2, n]], p = n}, While[k > -1 && !PrimeQ[p - 2^k], k-- ]; If[k > 0, True, False]]; Select[ Prime[ Range[536]], !fQ[ # ] &] (from Robert G. Wilson v Feb 10 2005)

PROG

(Haskell)

a065381 n = a065381_list !! (n-1)

a065381_list = filter f a000040_list where

   f p = all ((== 0) . a010051 . (p -)) $ takeWhile (<= p) a000079_list

-- Reinhard Zumkeller, Nov 24 2011

CROSSREFS

Equals A000040 minus A065380.

Cf. A010051, A006285, A102630, A094076.

Sequence in context: A064070 A139904 A167414 * A141928 A062588 A125634

Adjacent sequences:  A065378 A065379 A065380 * A065382 A065383 A065384

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 03 2001

EXTENSIONS

Fixed link and cross-reference. - Charles R Greathouse IV Nov 09 2008

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Last modified February 15 13:05 EST 2012. Contains 205789 sequences.