OFFSET
0,5
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..256
FORMULA
MATHEMATICA
a[n_]:=If[n<2, 0, Sum[BitAnd[Binomial[n - 1, k - 1], Binomial[n - 1, k]], {k, n - 1}]]; Table[a[n], {n, 0, 100}] (* Indranil Ghosh, Apr 16 2017 *)
PROG
(PARI) A285115(n) = if(n<2, 0, sum(k=1, (n-1), bitand(binomial(n-1, k-1), binomial(n-1, k))));
(Scheme)
(define (add intfun lowlim uplim) (let sumloop ((i lowlim) (res 0)) (cond ((> i uplim) res) (else (sumloop (+ 1 i) (+ res (intfun i)))))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Apr 16 2017
STATUS
approved