login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A100463
a(n) = 2^(n-1) - A100462(n).
2
0, 1, 3, 5, 9, 7, 15, 19, 27, 31, 21, 29, 45, 49, 75, 85, 97, 65, 63, 101, 153, 125, 157, 127, 177, 163, 165, 199, 229, 199, 217, 277, 253, 325, 315, 365, 345, 379, 423, 449, 549, 529, 597, 409, 507, 473, 633, 569, 717, 523, 651, 655, 777, 793, 825, 835, 855, 833
OFFSET
1,3
LINKS
MAPLE
A100461:= proc(m, n) option remember;
if m=1 then 2^(n-1);
else (n-m+1)*floor((A100461(m-1, n)-1)/(n-m+1));
fi; end:
A100462:= proc(n) A100461(n, n); end:
A100463:= proc(n) 2^(n-1) - A100462(n); end:
seq(A100463(n), n=1..100); # R. J. Mathar, Aug 06 2007
MATHEMATICA
t[n_, k_]:= t[n, k]= If[k==1, 2^(n-1), If[k<n+1, (n-k+1)*Floor[(t[n, k -1] -1)/(n-k+1)], 0]]; (* t = A100461 *)
Table[2^(n-1) -t[n, n], {n, 60}] (* G. C. Greubel, Apr 07 2023 *)
PROG
(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;
[2^(n-1) - t(n, n): n in [1..60]]; // 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))
[2^(n-1) - t(n, n) for n in range(1, 61)] # G. C. Greubel, Apr 07 2023
CROSSREFS
Sequence in context: A003961 A332818 A348437 * A346969 A166722 A094549
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Nov 23 2004
EXTENSIONS
More terms from R. J. Mathar, Aug 06 2007
STATUS
approved