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 A217593 Square array T, read by antidiagonals: T(n,k) = 0 if n-k >=1 or if k-n >= 9, T(0,k) = 1 for k = 0..8, T(n,k) = T(n-1,k) + T(n,k-1). 3
 1, 1, 0, 1, 1, 0, 1, 2, 0, 0, 1, 3, 2, 0, 0, 1, 4, 5, 0, 0, 0, 1, 5, 9, 5, 0, 0, 0, 1, 6, 14, 14, 0, 0, 0, 0, 1, 7, 20, 28, 14, 0, 0, 0, 0, 0, 8, 27, 48, 42, 0, 0, 0, 0, 0, 0, 8, 35, 75, 90, 42, 0, 0, 0, 0, 0, 0, 0, 43, 110, 165, 132, 0, 0, 0, 0, 0, 0, 0, 0, 43, 153, 275, 297, 132, 0, 0, 0, 0, 0, 0, 0, 0, 0, 196, 428, 572, 429, 0, 0, 0, 0, 0, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,8 REFERENCES A hexagon arithmetic of E. Lucas. LINKS FORMULA T(n,n)   = A033191(n). T(n,n+1) = A033191(n+1). T(n,n+2) = A033190(n+1). T(n,n+3) = A094667(n+1). T(n,n+4) = A093131(n+1) = A030191(n). T(n,n+5) = A094788(n+2). T(n,n+6) = A094825(n+3). T(n,n+7) = T(n,n+8) = A094865(n+3). Sum_{k, 0<=k<=n} T(n-k,k) = A178381(n). EXAMPLE Square array begins : 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, ... 0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 0, 0, ... 0, 0, 2, 5, 9, 14, 20, 27, 35, 43, 43, 0, 0, ... 0, 0, 0, 5, 14, 28, 75, 110, 153, 196, 196, 0, 0, .... 0, 0, 0, 0, 14, 42, 90, 165, 275, 428, 624, 820, 820, 0, 0, ... ... Square array, read by rows, with 0 omitted: 1, 1, 1, 1, 1, 1, 1, 1, 1 1, 2, 3, 4, 5, 6, 7, 8, 8 2, 5, 9, 14, 20, 27, 35, 43, 43 5, 14, 28, 48, 75, 110, 153, 196, 196 14, 42, 90, 165, 275, 428, 624, 820, 820 42, 132, 297, 572, 1000, 1624, 2444, 3264, 3264 132, 429, 1001, 2001, 3625, 6069, 9333, 12597, 12597 429, 1430, 3431, 7056, 13125, 22458, 35055, 47652, 47652 ... CROSSREFS Sequence in context: A216054 A217257 A217315 * A322279 A292861 A292133 Adjacent sequences:  A217590 A217591 A217592 * A217594 A217595 A217596 KEYWORD nonn,tabl AUTHOR Philippe Deléham, Mar 18 2013 STATUS approved

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Last modified October 15 10:15 EDT 2019. Contains 328026 sequences. (Running on oeis4.)