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 A185870 (Even,odd)-polka dot array in the natural number array A000027, by antidiagonals. 4
 3, 8, 10, 17, 19, 21, 30, 32, 34, 36, 47, 49, 51, 53, 55, 68, 70, 72, 74, 76, 78, 93, 95, 97, 99, 101, 103, 105, 122, 124, 126, 128, 130, 132, 134, 136, 155, 157, 159, 161, 163, 165, 167, 169, 171, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 278, 280, 282, 284, 286, 288, 290, 292, 294, 296, 298, 300, 327, 329, 331, 333, 335, 337, 339, 341, 343, 345, 347, 349, 351, 380, 382, 384, 386, 388, 390, 392, 394, 396, 398, 400, 402, 404, 406 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This is the third of four polka dot arrays in the array A000027. See A185868. row 1: A033816 col 1: A014105 col 2: -A168244 antidiagonal sums: A061317 antidiagonal sums: 3*(octahedral numbers) = 3*A005900. LINKS G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened FORMULA T(n,k) = 2*n + (n+k-1)*(2*n+2*k-3), k>=1, n>=1. EXAMPLE Northwest corner: 3....8....17...30...47 10...19...32...49...70 21...34...51...72...97 36...53...74...99...128 MATHEMATICA f[n_, k_]:=2n+(2n+2k-3)(n+k-1); TableForm[Table[f[n, k], {n, 1, 10}, {k, 1, 15}]] Table[f[n-k+1, k], {n, 14}, {k, n, 1, -1}]//Flatten CROSSREFS Cf. A000027 (as an array), A185868, A185869, A185871. Sequence in context: A128699 A104816 A181022 * A341938 A341939 A244353 Adjacent sequences: A185867 A185868 A185869 * A185871 A185872 A185873 KEYWORD nonn,tabl AUTHOR Clark Kimberling, Feb 05 2011 STATUS approved

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Last modified September 28 01:19 EDT 2023. Contains 365714 sequences. (Running on oeis4.)