|
Search: id:A065381
|
|
|
| A065381 |
|
Primes not of the form p + 2^k, p prime and k >= 0. |
|
+0
6
|
|
| 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; listen)
|
|
|
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.
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)
|
|
CROSSREFS
|
Equals A000040 minus A065380.
Cf. A006285, A102630, A094076.
Sequence in context: A064070 A139904 A167414 this_sequence A141928 A062588 A125634
Adjacent sequences: A065378 A065379 A065380 this_sequence 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
|
|
|
Search completed in 0.002 seconds
|
