A112989 Terms in A006899 which are closer to the next term than to the previous one.

8, 27, 64, 243, 512, 2048, 6561, 16384, 59049, 131072, 524288, 1594323, 4194304, 14348907, 33554432, 129140163, 268435456, 1073741824, 3486784401, 8589934592, 31381059609, 68719476736, 274877906944, 847288609443, 2199023255552

Offset

1,1

Comments

Next terms are: 17592186044416, 68630377364883, 140737488355328, 562949953421312, 1853020188851841, 4503599627370496, 16677181699666569, 36028797018963968, 144115188075855872, 450283905890997363, 1152921504606846976. Is the sequence infinite? Cf. A006899 Numbers of the form 2^i or 3^j.

Links

Table of n, a(n) for n=1..25.

Formula

A006899(n) - A006899(n-1) > A006899(n+1) - A006899(n)

Mathematica

un=Union[Flatten[Table[{2^n, 3^n}, {n, 60}]]]; Do[If[un[[i]]-un[[i-1]]>un[[i+1]]-un[[i]], Print[un[[i]]]], {i, 2, Length[un]-1}]

Crossrefs

Cf. A006899.

Sequence in context: A050462 A112662 A121652 * A018832 A248705 A030293

Adjacent sequences: A112986 A112987 A112988 * A112990 A112991 A112992

Keyword

nonn

Author

Zak Seidov, Jan 03 2006

Status

approved