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 A038374 Length of longest contiguous block of 1's in binary expansion of n. 22
 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 2, 2, 2, 3, 4, 1, 1, 1, 2, 1, 1, 2, 3, 2, 2, 2, 2, 3, 3, 4, 5, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 2, 2, 2, 3, 4, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 5, 6, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 2, 2, 2, 3, 4, 1, 1, 1, 2, 1, 1, 2, 3, 2, 2, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 FORMULA a(n) >= A089309(n). a(n) >= A089310(n). a(2^i)=1. a(2^i-1)=i. - R. J. Mathar, Jun 15 2006 May be defined by the recurrence given in A245196, taking G(n)=n+1 (n>=0) and m=1. - N. J. A. Sloane, Jul 25 2014 EXAMPLE a(157) = 3 because 157 in base 2 is 10011101 and longest contiguous block of 1's is of length 3. May be arranged into blocks of lengths 1, 2, 4, 8, 16, ...: 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 2, 2, 2, 3, 4, 1, 1, 1, 2, 1, 1, 2, 3, 2, 2, 2, 2, 3, 3, 4, 5, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 2, 2, 2, 3, 4, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 5, 6, ... - N. J. A. Sloane, Jul 25 2014 MAPLE A038374 := proc(n) local nshft, thisr, resul; nshft := n ; resul :=0 ; thisr :=0 ; while nshft > 0 do if nshft mod 2 <> 0 then thisr := thisr+1 ; else resul := max(resul, thisr) ; thisr := 0 ; fi ; nshft := floor(nshft/2) ; od ; resul := max(resul, thisr) ; RETURN(resul) ; end : for n from 1 to 80 do printf("%d, ", A038374(n)) ; od : # R. J. Mathar, Jun 15 2006 MATHEMATICA Table[Max[Length/@DeleteCases[Split[IntegerDigits[n, 2]], _?(MemberQ[ #, 0] &)]], {n, 120}] (* Harvey P. Dale, Jun 10 2013 *) PROG (Haskell) import Data.List (unfoldr, group) a038374 = maximum . map length . filter ((== 1) . head) . group .    unfoldr (\x -> if x == 0 then Nothing else Just \$ swap \$ divMod x 2) -- Reinhard Zumkeller, May 01 2012 (PARI) a(n)=if (n==0, return (0)); n>>=valuation(n, 2); if(n<2, return(n)); my(e=valuation(n+1, 2)); max(e, a(n>>e)) \\ Charles R Greathouse IV, Jan 12 2014; edited by Michel Marcus, Apr 14 2019 CROSSREFS Cf. A087117, A090000, A090001, A090002, A090003, A090050, A245196. Sequence in context: A265754 A089309 A126387 * A284569 A272604 A284580 Adjacent sequences:  A038371 A038372 A038373 * A038375 A038376 A038377 KEYWORD base,easy,nonn,tabf AUTHOR STATUS approved

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Last modified May 24 18:34 EDT 2019. Contains 323534 sequences. (Running on oeis4.)