A110968 a(n) is the starting position of the first run of n ones in A014963.

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

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