login
A328196
First differences of A328190.
7
2, 4, -2, 6, -3, 9, -7, 12, -9, 14, -12, 16, -13, 19, -17, 21, -18, 24, -22, 26, -23, 29, -27, 32, -29, 34, -32, 36, -33, 39, -37, 42, -39, 44, -42, 46, -43, 49, -47, 52, -49, 54, -52, 56, -53, 59, -57, 61, -58, 64, -62, 66, -63, 69, -67, 72, -69, 74, -72, 76
OFFSET
1,1
COMMENTS
Conjecture from N. J. A. Sloane, Nov 05 2019: (Start)
a(4t) = 5t+1(+1 if binary expansion of t ends in odd number of 0's) for t >= 1,
a(4t+1) = -(5t-2(+1 if binary expansion of t ends in odd number of 0's)) for t >= 1,
a(4t+2) = 5t+4 for t >= 0,
a(4t+3) = -(5t+2) for t >= 0.
These formulas explain all the known terms.
a(2t) is closely related to A298468. The expressions for a(4t) and a(4t+1) can also be written in terms of A328979.
The conjecture would establish that the terms lie on two straight lines, of slopes +-5/4.
There is a similar conjecture for A328190. (End)
CROSSREFS
The negative terms are (conjecturally) listed in A329982 (see also A328983).
See A328984 and A328985 for simpler sequences which almost have the properties of A329190 and A328196. - N. J. A. Sloane, Nov 07 2019
Sequence in context: A360005 A360457 A328985 * A323307 A215841 A272327
KEYWORD
sign
AUTHOR
Peter Kagey, Oct 07 2019
STATUS
approved