A373895 - OEIS

%I #16 Jun 21 2024 14:19:24

%S 2,3,4,5,8,12,20,33,58,104,188,343,632,1172,2186,4097,7712,14565,

%T 27596,52430,99866,190652,364724,699052,1342179,2581112,4971028,

%U 9586982,18512792,35791396,69273668,134217729,260301050,505290272,981706812,1908874355,3714566312,7233629132,14096302922,27487790696

%N a(n) = ceiling((2^n+n-1)/n).

%C a(n) is the irregularity strength of the hypercube graph Q_n for n >= 2.

%H Michael De Vlieger, <a href="/A373895/b373895.txt">Table of n, a(n) for n = 1..3333</a>

%H G. Ebert, J. Hammenter, F. Lazebnik, and A. Woldar, <a href="https://www.researchgate.net/publication/246544317_Irregularity_Strengths_For_Certain_Graphs">Irregularity Strengths for Certain Graphs</a>, Congressus Numerantium 71 (1990), 39-52.

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HypercubeGraph.html">Hypercube Graph</a>.

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/IrregularityStrength.html">Irregularity Strength</a>.

%t Array[Ceiling[(2^# + # - 1)/#] &, 120] (* _Michael De Vlieger_, Jun 21 2024 *)

%Y Cf. A052944, A053638, A082482.

%K nonn,easy

%O 1,1

%A _Eric W. Weisstein_, Jun 21 2024