This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A110425 #5 Dec 05 2013 19:57:02
%S A110425 1,2,1,3,3,-3,4,5,0,-14,5,7,3,-10,-35,6,9,6,-6,-30,-69,7,11,9,-2,-25,
%T A110425 -63,-119,8,13,12,2,-20,-57,-112,-188,9,15,15,6,-15,-51,-105,-180,
%U A110425 -279,10,17,18,10,-10,-45,-98,-172,-270,-395,11,19,21,14,-5,-39,-91,-164,-261,-385,-539,12,21,24,18,0,-33,-84,-156,-252
%N A110425 The r-th term of the n-th row of the following array contains the sum of r successively decreasing integers beginning from n. 0<r<=n. e.g. the row corresponding to 4 contains 4, (3+2),{(1) +(0)+(-1)}, {(-2)+(-3)+(-4)+(-5)} ----> 4,5,0,-14 1 2 1 3 3 -3 4 5 0 -14 5 7 3 -10 -35 6 9 6 -6 -30 -69 ... Sequence contains the array by rows.
%e A110425 The r-th term of the n-th row of the following array contains the sum of r successively decreasing integers beginning from n. 0<r<=n.
%e A110425 e.g. the row corresponding to 4 contains
%e A110425 4, (3+2),{(1) +(0)+(-1)}, {(-2)+(-3)+(-4)+(-5)} ----> 4,5,0,-14
%e A110425 1
%e A110425 2 1
%e A110425 3 3 -3
%e A110425 4 5 0 -14
%e A110425 5 7 3 -10 -35
%e A110425 Sequence contains the array by rows.
%o A110425 ;;PLT DrScheme (Zucker)
%o A110425 (define (triangle n) (* n (add1 n) 1/2))
%o A110425 (define (A110425 n)
%o A110425 (build-list n (lambda (r) (- (triangle (- n (triangle r)))
%o A110425 (triangle (- n (triangle (add1 r))))))))
%Y A110425 Cf. A110426, A110427.
%K A110425 easy,sign,tabl
%O A110425 1,2
%A A110425 _Amarnath Murthy_, Aug 01 2005
%E A110425 More terms from _Joshua Zucker_, May 10 2006