A160415 First differences of A160118.

1, 8, 4, 28, 4, 28, 12, 84, 4, 28, 12, 84, 12, 84, 36, 252, 4, 28, 12, 84, 12, 84, 36, 252, 12, 84, 36, 252, 36, 252, 108, 756, 4, 28, 12, 84, 12, 84, 36, 252, 12, 84, 36, 252, 36, 252, 108, 756, 12, 84, 36, 252, 36, 252, 108, 756, 36, 252, 108, 756, 108, 756, 324

Offset: 1

Author

Omar E. Pol, Jun 13 2009

Keywords

• nonn

Comments

Number of cells turned "ON" at n-th stage of the cellular automaton of A160118.

Examples

			From _Omar E. Pol_, Mar 21 2011: (Start)
If written as a triangle begins:
1,
8,
4,28,
4,28,12,84,
4,28,12,84,12,84,36,252,
4,28,12,84,12,84,36,252,12,84,36,252,36,252,108,756,
(End)
		

Links

• Index entries for sequences related to cellular automata.

Crossrefs

Cf. A139251, A160118, A160411, A160413, A160417.

Programs

Mathematica

With[{d = 2}, wt[n_] := DigitCount[n, 2, 1]; f[n_] := If[OddQ[n], 3^d + (2^d) * Sum[(2^d - 1)^(wt[k] - 1), {k, 1, (n - 1)/2}] + (2^d)*(3^d - 2) * Sum[(2^d - 1)^(wt[k] - 1), {k, 1, (n - 3)/2}], 3^d + (2^d) * Sum[(2^d - 1)^(wt[k] - 1), {k, 1, n/2 - 1}] + (2^d)*(3^d - 2) * Sum[(2^d - 1)^(wt[k] - 1), {k, 1, n/2 - 1}]]; f[0] = 0; f[1] = 1; Differences[Array[f, 100, 0]]] (* Amiram Eldar, Feb 02 2024 *)

Extensions

More terms (a(8)-a(38)) from Nathaniel Johnston, Nov 14 2010

21 terms corrected between a(13) and a(38), and more terms (a(39)-a(48)) from Omar E. Pol, Mar 21 2011

More terms from Amiram Eldar, Feb 02 2024