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 A099627 Triangle read by rows: T(n,k)=2^n+2^k-1 with n>=k>=0. 13
 1, 2, 3, 4, 5, 7, 8, 9, 11, 15, 16, 17, 19, 23, 31, 32, 33, 35, 39, 47, 63, 64, 65, 67, 71, 79, 95, 127, 128, 129, 131, 135, 143, 159, 191, 255, 256, 257, 259, 263, 271, 287, 319, 383, 511, 512, 513, 515, 519, 527, 543, 575, 639, 767, 1023, 1024, 1025, 1027, 1031, 1039 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Positive integers m where m-th Catalan number A000108(m)=C(2m,m)/(m+1) is not divisible by 4, i.e. where A048881(m) is 0 or 1. Numbers in A000225 or A099628. LINKS Reinhard Zumkeller, Rows n = 0..100 of triangle, flattened FORMULA As sequence, a(n)=A048645(n+2)-1. EXAMPLE Triangle starts:                  In binary:    k = 0  1  2  3  4  5 n 0      1                               1 1      2  3                           10     11 2      4  5  7                       100    101    111 3      8  9 11 15                   1000   1001   1011   1111 4     16 17 19 23 31               10000  10001  10011  10111  11111 5     32 33 35 39 47 63           100000 100001 100011 100111 101111 111111 E.g. T(5,3) = 2^5 + 2^3-1 = 32 + 7 = 39 (100111 in binary). MATHEMATICA Table[2^n+2^k -1, {n, 0, 10}, {k, 0, n}]//Flatten (* Harvey P. Dale, Mar 27 2016 *) PROG (Haskell) a099627 n k = a099627_tabl !! n !! k a099627_row n = a099627_tabl !! n a099627_tabl = iterate (\xs@(x:_) -> (2 * x) : map ((+ 1) . (* 2)) xs) [1] -- Reinhard Zumkeller, Dec 19 2012 CROSSREFS A053221 (row sums), A000079 (left diagonal), A000225 (right diagonal). A048645 (see formula). Sequence in context: A140691 A328668 A316468 * A324841 A184155 A318612 Adjacent sequences:  A099624 A099625 A099626 * A099628 A099629 A099630 KEYWORD easy,nonn,tabl AUTHOR Henry Bottomley, Oct 25 2004 STATUS approved

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Last modified December 13 06:26 EST 2019. Contains 329968 sequences. (Running on oeis4.)