A119445 Leading diagonal of triangle A119444.

1, 1, 1, 1, 1, 3, 7, 13, 27, 63, 109, 207, 331, 553, 931, 1531, 2527, 4093, 6673, 10831, 17563, 28561, 46227, 74883, 121219, 196239, 317607, 514047, 831823, 1346041, 2178079, 3524323, 5702619, 9227161, 14930019, 24157471, 39087823, 63245551

Offset

1,6

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Formula

a(n) = A119444(n, n).

Mathematica

t[1, n_]:= Fibonacci[n+1];  (* t = A119444 *)
t[m_, n_]/; 1<m<=n:= t[m, n]= (n-m+1)*Floor[(t[m-1, n] -1)/(n-m+1)];
t[_, _]= 0;
A119445[n_]:= A119445[n]= t[n, n];
Table[A119445[n], {n, 60}] (* G. C. Greubel, Apr 07 2023 *)

Prog

(Magma)
function t(n, k) // t = A119444
  if k eq 1 then return Fibonacci(n+1);
  else return (n-k+1)*Floor((t(n, k-1) -1)/(n-k+1));
  end if;
end function;
[t(n, n): n in [1..60]]; // G. C. Greubel, Apr 07 2023
(SageMath)
def t(n, k): # t = A119444
    if (k==1): return fibonacci(n+1)
    else: return (n-k+1)*((t(n, k-1) -1)//(n-k+1))
def A119445(n): return t(n, n)
[A119445(n) for n in range(1, 61)] # G. C. Greubel, Apr 07 2023

Crossrefs

Cf. A119444 for triangle corresponding to this sequence.

Cf. A100461 for powers of 2, A119446 for primes.

Sequence in context: A301594 A080241 A098479 * A146904 A146432 A258349

Adjacent sequences: A119442 A119443 A119444 * A119446 A119447 A119448

Keyword

nonn

Author

Joshua Zucker, May 20 2006

Status

approved