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A110968 a(n) is the starting position of the first run of n ones in A014963. 1
1, 14, 20, 33, 54, 1025, 90, 513, 140, 536870913, 200, 144115188075855860, 294, 65522, 1832, 8193, 1070, 147573952589676412910, 888, 524289, 1130, 549755813889, 4178, 17179869185, 2478, 16385, 2972, 131073, 1332, 34359738338, 5592, 18014398509481952, 8468 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Probably a(n) exists for every n in N.

If n = 2*k, then a(n) - 1 or a(n) + n is of the form 2^e. - Jinyuan Wang, Mar 21 2020

LINKS

Franz Vrabec, Table of n, a(n) for n = 1..250

EXAMPLE

a(3) = 20 because the first run of 3 ones in A014963 begins at position 20.

PROG

(PARI) a(n) = if(n%2, my(c=0); for(k=1, oo, if(isprimepower(k), if(c==n, return(k-n), c=0), c++)), my(m=1); for(k=1, oo, m*=2; if(isprimepower(m-n-1) && sum(i=m-n, m-1, isprimepower(i))==0, return(m-n)); if(isprimepower(m+n+1) && sum(i=m+1, m+n, isprimepower(i))==0, return(m+1)))); \\ Jinyuan Wang, Mar 21 2020

CROSSREFS

Cf. A014963.

Sequence in context: A285426 A108874 A063848 * A054017 A129216 A259536

Adjacent sequences:  A110965 A110966 A110967 * A110969 A110970 A110971

KEYWORD

nonn

AUTHOR

Franz Vrabec, Sep 27 2005

STATUS

approved

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Last modified August 2 17:49 EDT 2021. Contains 346428 sequences. (Running on oeis4.)