A010752 - OEIS

%I #21 Feb 10 2022 08:32:44

%S 1,1,1,3,4,5,12,17,23,50,73,103,211,314,455,895,1350,1993,3805,5798,

%T 8679,16193,24872,37633,68940,106573,162643,293526,456169,701075,

%U 1249622,1950697,3015563,5318976,8334539,12948083,22634700,35582783,55513327,96296410

%N Sum along upward diagonal of Pascal triangle to center.

%H Seiichi Manyama, <a href="/A010752/b010752.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) = Sum_{k=0..floor(n/3)} binomial(n - k, k). - _Sean A. Irvine_, Jun 08 2018

%o (PARI) a(n) = sum(k=0, n\3, binomial(n-k, k)); \\ _Seiichi Manyama_, Feb 10 2022

%Y Cf. A000045, A007318, A010753, A010756, A010757.

%K nonn

%O 0,4

%A _R. K. Guy_