cp's OEIS Frontend

A088487 a(n) = Sum_{k=1..8} floor(A254864(n,k)/A254864(n-1,k)), where A254864(n,k) = n! / (n-floor(n/3^k))!.

%I A088487 #21 Dec 18 2022 02:33:21
%S A088487 8,10,8,8,13,8,8,24,8,8,19,8,8,22,8,8,42,8,8,28,8,8,31,8,8,86,8,8,37,
%T A088487 8,8,40,8,8,78,8,8,46,8,8,49,8,8,96,8,8,55,8,8,58,8,8,167,8,8,64,8,8,
%U A088487 67,8,8,132,8,8,73,8,8,76,8,8,150,8,8,82,8,8,85,8,8,328,8,8,91,8,8,94,8,8
%N A088487 a(n) = Sum_{k=1..8} floor(A254864(n,k)/A254864(n-1,k)), where A254864(n,k) = n! / (n-floor(n/3^k))!.
%H A088487 Antti Karttunen, <a href="/A088487/b088487.txt">Table of n, a(n) for n = 2..10000</a>
%F A088487 a(n) = Sum_{k=1..8} floor(A254864(n,k)/A254864(n-1,k)), where A254864(n,k) = n! / (n-floor(n/3^k))!.
%t A088487 p[n_, k_]=n!/Product[i, {i, 1, n-Floor[n/3^k]}] digits=200 f[n_]=Sum[Floor[p[n, k]/p[n-1, k]], {k, 1, 8}] at=Table[f[n], {n, 2, digits}]
%o A088487 (PARI)
%o A088487 A254864bi(n,k) = prod(i=(1+(n-(n\(3^k)))),n,i);
%o A088487 A088487(n) = sum(k=1,8,(A254864bi(n,k)\A254864bi(n-1,k)));
%o A088487 for(n=2, 10000, write("b088487.txt", n, " ", A088487(n)));
%o A088487 (Scheme)
%o A088487 (define (A088487 n) (add (lambda (k) (floor->exact (/ (A254864bi n k) (A254864bi (- n 1) k)))) 1 8)) ;; Code for A254864bi given in A254864.
%o A088487 ;; The following function implements sum_{i=lowlim..uplim} intfun(i)
%o A088487 (define (add intfun lowlim uplim) (let sumloop ((i lowlim) (res 0)) (cond ((> i uplim) res) (else (sumloop (1+ i) (+ res (intfun i)))))))
%Y A088487 Cf. A254864, A088488.
%K A088487 nonn,less
%O A088487 2,1
%A A088487 _Roger L. Bagula_, Nov 09 2003
%E A088487 Edited by _Antti Karttunen_, Feb 09 2015