A073141 Product of the largest and smallest number having in binary representation the same number of 0's and 1's as n.

0, 1, 4, 9, 16, 30, 30, 49, 64, 108, 108, 154, 108, 154, 154, 225, 256, 408, 408, 532, 408, 532, 532, 690, 408, 532, 532, 690, 532, 690, 690, 961, 1024, 1584, 1584, 1960, 1584, 1960, 1960, 2340, 1584, 1960, 1960, 2340, 1960, 2340, 2340, 2914, 1584, 1960

Offset: 0

Author

Reinhard Zumkeller, Jul 16 2002

Keywords

• nonn

Comments

a(n) = A073137(n) * A073138(n).

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000
• Index entries for sequences related to binary expansion of n

Crossrefs

Cf. A007088, A073139, A073140.

Programs

Mathematica

pls[n_]:=With[{d=FromDigits[#,2]&/@Select[Permutations[IntegerDigits[n,2]],#[[1]]==1&]},Max[d]Min[d]]; Join[{0},Array[pls,50]] (* Harvey P. Dale, May 29 2025 *)