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b + c + d where b >= c >= d >= 0 ordered by b then c then d.
7

%I #15 May 09 2024 19:33:44

%S 0,1,2,3,2,3,4,4,5,6,3,4,5,5,6,7,6,7,8,9,4,5,6,6,7,8,7,8,9,10,8,9,10,

%T 11,12,5,6,7,7,8,9,8,9,10,11,9,10,11,12,13,10,11,12,13,14,15,6,7,8,8,

%U 9,10,9,10,11,12,10,11,12,13,14,11,12,13,14,15,16,12,13,14,15,16,17,18,7

%N b + c + d where b >= c >= d >= 0 ordered by b then c then d.

%H Robert Israel, <a href="/A070770/b070770.txt">Table of n, a(n) for n = 0..10000</a>

%F a(n) = A056556(n) + A056557(n) + A056558(n).

%p seq(seq(seq(b+c+d,d=0..c),c=0..b),b=0..10); # _Robert Israel_, Jun 21 2018

%o (PARI) for(x=0,5,for(y=0,x,for(z=0,y,print1(x+y+z", ")))) \\ _Charles R Greathouse IV_, Sep 17 2015

%Y Cf. A001477, A051162, A070771, A070772 for similar sequences with different numbers of terms summed.

%K nonn,look,tabf

%O 0,3

%A _Henry Bottomley_, May 06 2002