A092674 Derived from a(n)=binomial(n+1,2) - sum{i=1,n-1,a(i)*floor(n/i)} (see A000010) - this is the value of the constant term.

0, 3, 3, 1, 5, 0, 7, 4, 6, 2, 11, 5, 13, 4, 7, 8, 17, 6, 19, 9, 11, 8, 23, 8, 20, 10, 18, 13, 29, 10, 31, 16, 19, 14, 23, 12, 37, 16, 23, 16, 41, 14, 43, 21, 24, 20, 47, 16, 42, 20, 31, 25, 53, 18, 39, 24, 35, 26, 59, 15, 61, 28, 36, 32, 47, 22, 67, 33, 43, 26, 71, 24, 73, 34, 40

Offset

1,2

Comments

It is conjectured that a(n) is never less than 0 (tested to n=2000)

Links

Table of n, a(n) for n=1..75.

Example

The formula produces the initial output:
x, -2*x + 3, -x + 3, x + 1, -x + 5, 2*x, -x + 7, 4, 6, 2*x + 2, -x + 11, -x + 5, -x + 13, 2*x + 4, x + 7, 8, -x + 17, 6, -x + 19, -x + 9, x + 11, 2*x + 8, -x + 23, 8, 20, 2*x + 10, 18, -x + 13, -x + 29, -2*x + 10, -x + 31, 16, x + 19.
The sequence gives the constant term.

Prog

(PARI) s=vector(200); t(n)=binomial(n+1, 2); s[1]=x; for(i=2, 200, s[i]=t(i)-sum(j=1, i-1, s[j]*floor(i/j))); for(i=1, 200, print1(", "polcoeff(s[i], 0)))

Crossrefs

Cf. A092673.

Sequence in context: A327148 A366595 A327237 * A316366 A111945 A002143

Adjacent sequences: A092671 A092672 A092673 * A092675 A092676 A092677

Keyword

nonn

Author

Jon Perry, Mar 02 2004

Status

approved