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A119445
Leading diagonal of triangle A119444.
2
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
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
KEYWORD
nonn
AUTHOR
Joshua Zucker, May 20 2006
STATUS
approved