A246336 Partial sums of A151548.

1, 4, 9, 16, 21, 32, 49, 64, 69, 80, 97, 116, 137, 176, 225, 256, 261, 272, 289, 308, 329, 368, 417, 452, 473, 512, 565, 624, 705, 832, 961, 1024, 1029, 1040, 1057, 1076, 1097, 1136, 1185, 1220, 1241, 1280, 1333, 1392, 1473, 1600, 1729, 1796, 1817, 1856, 1909, 1968, 2049, 2176

Offset

0,2

Comments

Arises in the analysis of a certain 2-D cellular automaton (see A169707).

a(46) = 1729 is also the Hardy-Ramanujan number. - Omar E. Pol, Feb 17 2015

It appears that sums of two successive terms give the numbers greater than 1 in A194811. - Omar E. Pol, Mar 05 2015

Links

N. J. A. Sloane, Table of n, a(n) for n = 0..10000

N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

Index entries for sequences related to cellular automata

Formula

G.f.: 1/(1-x^2) + (4*x/(1-x))*mul(1+x^(2^k-1)+2*x^(2^k),k=1..oo).

From Omar E. Pol, Feb 18 2015: (Start)

It appears that:

a(2^k-2) = (2^k-1)^2, if k >= 1.

a(2^k-1) = 4^k, if k >= 1.

a(2^k) = 4^k + 5, if k >= 1.

(End)

Crossrefs

Cf. A169707, A151548, A160552, A170903.

Sequence in context: A360927 A313343 A261849 * A232656 A364699 A010460

Adjacent sequences: A246333 A246334 A246335 * A246337 A246338 A246339

Keyword

nonn,look

Author

N. J. A. Sloane, Aug 30 2014

Status

approved