A328196 First differences of A328190.

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

Author

Peter Kagey, Oct 07 2019

Keywords

• sign

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)

Links

• Peter Kagey, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A298468, A328190, A328979.

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