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

Author

N. J. A. Sloane, Aug 30 2014

Keywords

• nonn
• look

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

Crossrefs

Cf. A169707, A151548, A160552, A170903.

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)