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 A125179 Triangle read by rows: T(n,1) = prime(n) (the n-th prime); T(n,k) = 0 for k > n; T(n,k) = T(n-1,k) + T(n-1,k-1) for 2 <= k <= n (1 <= k <= n). 2
 2, 3, 2, 5, 5, 2, 7, 10, 7, 2, 11, 17, 17, 9, 2, 13, 28, 34, 26, 11, 2, 17, 41, 62, 60, 37, 13, 2, 19, 58, 103, 122, 97, 50, 15, 2, 23, 77, 161, 225, 219, 147, 65, 17, 2, 29, 100, 238, 386, 444, 366, 212, 82, 19, 2, 31, 129, 338, 624, 830, 810, 578, 294, 101, 21, 2, 37, 160, 467 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Sum of row n = A125180(n). LINKS Table of n, a(n) for n=1..69. FORMULA T(n,2) = A007504(n-1) (n>=2). EXAMPLE Triangle starts: 2; 3, 2; 5, 5, 2; 7, 10, 7, 2; 11, 17, 17, 9, 2; 13, 28, 34, 26, 11, 2; 17, 41, 62, 60, 37, 13, 2; MAPLE T:=proc(n, k) if k=1 then ithprime(n) elif k>n then 0 else T(n-1, k)+T(n-1, k-1) fi end: for n from 1 to 12 do seq(T(n, k), k=1..n) od; # yields sequence in triangular form MATHEMATICA nmax = 11; row[1] = Prime[Range[nmax]]; row[n_] := row[n] = row[n-1] // Accumulate; T[n_, k_] := row[n][[k]]; Table[T[n-k+1, k], {n, 1, nmax}, {k, n, 1, -1}] // Flatten (* Jean-François Alcover, Oct 11 2021 *) CROSSREFS Cf. A125180 (row sums), A007442, A254858 (rows reversed). Cf. A007504. Sequence in context: A178144 A357987 A135737 * A141821 A144308 A144307 Adjacent sequences: A125176 A125177 A125178 * A125180 A125181 A125182 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Nov 22 2006 EXTENSIONS Edited by N. J. A. Sloane, Dec 02 2006 STATUS approved

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Last modified April 15 20:47 EDT 2024. Contains 371696 sequences. (Running on oeis4.)