[go: up one dir, main page]

login
Numbers that are not the sum of distinct lucky-indexed lucky numbers.
1

%I #9 Jul 25 2019 06:47:06

%S 2,3,4,5,6,9,10,11,12,13,14,15,16,17,18,19,20,23,24,25,26,27,30,33,34,

%T 35,36,37,40,41,42,43,44,45,46,47,48,51,54,55,58,61,62,65,66,67,68,69,

%U 72,73,74,75,76,79,82,83,86,89,90,93,96,97,98,99,100,103

%N Numbers that are not the sum of distinct lucky-indexed lucky numbers.

%C Analogous to A213356 with primes instead of lucky numbers.

%C Conjecture: this sequence is finite with the last term being a(98) = 373.

%H Amiram Eldar, <a href="/A319824/b319824.txt">Table of n, a(n) for n = 1..98</a>

%t L = Table[2*i + 1, {i, 0, 2500}]; For[n = 2, n < Length[L], r = L[[n++]]; L = ReplacePart[L, Table[r*i -> Nothing, {i, 1, Length[L]/r}]]]; a = L[[Select[L, # <= Length[L] &]]]; nn=Length[a]; t=Rest[CoefficientList[Series[Product[(1+x^(a [[k]])), {k, nn}], {x, 0, nn*nn}], x]]; Flatten[Position[t, 0]] (* after Jean-François Alcover at A000959 *)

%Y Cf. A000959, A032639, A213356, A318487.

%K nonn

%O 1,1

%A _Amiram Eldar_, Sep 28 2018