cp's OEIS Frontend

A104516 a(n) is the first occurrence of k in A104515, the difference between the maximum number of consecutive integers and the minimum number >1 of consecutive integers, the sum of which equals n.

%I A104516 #4 Mar 30 2012 17:31:12
%S A104516 1,9,30,15,21,35,54,45,55,77,156,91,105,135,204,153,171,209,252,231,
%T A104516 253,299,450,325,351,405,522,435,465,527,594,561,595,665,888,703,741,
%U A104516 819,984,861,903,989
%N A104516 a(n) is the first occurrence of k in A104515, the difference between the maximum number of consecutive integers and the minimum number >1 of consecutive integers, the sum of which equals n.
%C A104516 a(n)=0 iff n=2^k.
%C A104516 Where a(n)=k & a(n+2)=k+1 for k=54,252,594,...
%D A104516 Alfred S. Posamentier, Math Charmers, Tantalizing Tidbits for the Mind, Prometheus Books, NY, 2003, page 67.
%e A104516 a(2)=30 because 4+5+6+7+8 = 9+10+11 = 30.
%t A104516 f[n_] := Block[{r = Ceiling[n/2]}, If[ IntegerQ[ Log[2, n]], 0, m = Range[r]; lst = Flatten[ Table[ m[[k]], {i, r}, {j, i + 1, r}, {k, i, j}], 1]; l = Length /@ lst[[ Flatten[ Position[ Plus @@@ lst, n]]]]; Max[l] - Min[l]]]; t = Table[0, {50}]; Do[ c = f[n]; If[ t[[c + 1]] == 0, t[[c + 1]] = n; Print[{n, c}]], {n, 10^4}]; t
%Y A104516 Cf. A104512, A104513, A104514, A104515.
%K A104516 nonn
%O A104516 0,2
%A A104516 Alfred S. Posamentier (asp2(AT)juno.com) and _Robert G. Wilson v_, Feb 23 2005