A208241 Smallest prime greater than n, with n as prefix in binary representation.
2, 5, 7, 17, 11, 13, 29, 17, 19, 41, 23, 97, 53, 29, 31, 67, 71, 37, 79, 41, 43, 89, 47, 97, 101, 53, 109, 113, 59, 61, 127, 131, 67, 137, 71, 73, 149, 307, 79, 163, 83, 337, 173, 89, 181, 373, 191, 97, 197, 101, 103, 211, 107, 109, 223, 113, 229, 233, 239
Offset: 1
Links
- Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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Haskell
import Data.List (genericIndex, find, isPrefixOf) import Data.Maybe (fromJust) a208241 = genericIndex a208241_list a208241_list = f nns $ filter ((== 1) . a010051' . fst) nns where f mms'@((m,ms):mms) pps'@((p,ps):pps) = if m == p then f mms' pps else q : f mms pps' where q = fst $ fromJust $ find ((ms `isPrefixOf`) . snd) pps' nns = zip [1..] $ map reverse $ tail a030308_tabf -
Maple
A208241 := proc(n) local nbin,len,suf,sufbin,pbin,p ; nbin := convert(n,base,2) ; for len from 1 do for suf from 0 to 2^len-1 do sufbin := convert(suf,base,2) ; while nops(sufbin) < len do sufbin := [op(sufbin),0] ; end do: pbin := [op(sufbin),op(nbin)] ; p := add( 2^(i-1)*op(i,pbin),i=1..nops(pbin) ) ; if isprime(p) then return p ; end if; end do: end do: end proc: seq(A208241(n),n=1..50) ; # R. J. Mathar, May 06 2017
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