A100462 Leading diagonal of array in A100461.

1, 1, 1, 3, 7, 25, 49, 109, 229, 481, 1003, 2019, 4051, 8143, 16309, 32683, 65439, 131007, 262081, 524187, 1048423, 2097027, 4194147, 8388481, 16777039, 33554269, 67108699, 134217529, 268435227, 536870713, 1073741607, 2147483371, 4294967043, 8589934267, 17179868869

Offset: 1

Author

N. J. A. Sloane, Nov 22 2004

Keywords

• nonn

Links

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

Crossrefs

Cf. A100461, A100463.

Programs

Magma

function t(n,k) // t = A100461
  if k eq 1 then return 2^(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..40]]; // G. C. Greubel, Apr 07 2023

Mathematica

t[n_, k_]:= t[n, k]= If[k==1, 2^(n-1), (n-k+1)*Floor[(t[n,k-1] -1)/(n - k+1)]]; (* t = A100461 *)
Table[t[n,n], {n,40}] (* G. C. Greubel, Apr 07 2023 *)

SageMath

def t(n,k): # t = A100461
    if (k==1): return 2^(n-1)
    else: return (n-k+1)*((t(n, k-1) -1)//(n-k+1))
[t(n,n) for n in range(1,41)] # G. C. Greubel, Apr 07 2023