The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A275331 Triangle read by rows, T(n,k) = k*Sum_{m=1..n/k} t(k)*t(n-k*m+1) with t = A000081, for n>=1 and 1<=k<=n. 1
 1, 2, 2, 4, 2, 6, 8, 6, 6, 16, 17, 10, 12, 16, 45, 37, 24, 30, 32, 45, 120, 85, 50, 60, 64, 90, 120, 336, 200, 120, 132, 160, 180, 240, 336, 920, 486, 280, 318, 336, 405, 480, 672, 920, 2574, 1205, 692, 750, 800, 945, 1080, 1344, 1840, 2574, 7190 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS EXAMPLE Triangle starts: [n] [k=1,2,...] row sum [1] [1] 1 [2] [2, 2] 4 [3] [4, 2, 6] 12 [4] [8, 6, 6, 16] 36 [5] [17, 10, 12, 16, 45] 100 [6] [37, 24, 30, 32, 45, 120] 288 [7] [85, 50, 60, 64, 90, 120, 336] 805 [8] [200, 120, 132, 160, 180, 240, 336, 920] 2288 [9] [486, 280, 318, 336, 405, 480, 672, 920, 2574] 6471 PROG (Sage) @cached_function def t():     n = 1     b = [0, 1]     while True:         S = [k*sum(b[k]*b[n-k*m+1] for m in (1..n//k)) for k in (1..n)]         b.append(sum(S)//n)         yield S         n += 1 t_list = t() for n in (1..8): print(next(t_list)) CROSSREFS T(n,0) = A087803(n). T(n,n) = A055544(n). Sum_k T(n,k) = A095350(n+1). Cf. A000081, A275330. Sequence in context: A307536 A248842 A286538 * A308828 A325683 A331121 Adjacent sequences:  A275328 A275329 A275330 * A275332 A275333 A275334 KEYWORD nonn,tabl AUTHOR Peter Luschny, Aug 18 2016 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 31 04:43 EDT 2020. Contains 334747 sequences. (Running on oeis4.)