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

Author

Jon Perry, Mar 02 2004

Keywords

• nonn

Comments

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

Examples

			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.
		

Crossrefs

Cf. A092673.

Programs

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)))