A259964 A specially constructed B_2 sequence with sum of reciprocals greater than that of the Mian-Chowla sequence A005282.

1, 2, 4, 8, 13, 21, 31, 45, 66, 81, 97, 123, 148, 182, 229, 257, 290, 312, 381, 419, 467, 507, 621, 721, 770, 864, 927, 1050, 1178, 1289, 1457, 1561, 1615, 1774, 1907, 2090, 2164, 2263, 2309, 2539, 2800, 2938, 3035, 3310, 3380, 3738, 4043, 4239, 4439, 4726, 4851, 5016, 5169, 5289, 5490, 5760, 6646, 6843, 7015, 7442, 7674, 7986, 8284, 8506, 8772, 9240, 9778, 9996, 10344, 10431, 11614, 12263

Offset

1,2

Comments

Constructed using the greedy algorithm (as for A005252) except at 15th term, which is 229.

It had been conjectured that the sum of reciprocals for B_2 sequences was maximized by A005282. This sequence gives a counterexample.

Links

Table of n, a(n) for n=1..72.

Zhang Zhen-Xiang, A B_2-sequence with larger reciprocal sum, Math. Comp. 60 (1993), 835-839.

Crossrefs

Cf. A005282.

Sequence in context: A004978 A005282 A046185 * A218913 A349061 A241691

Adjacent sequences: A259961 A259962 A259963 * A259965 A259966 A259967

Keyword

nonn

Author

N. J. A. Sloane, Jul 11 2015

Status

approved