A080231 Engel expansion for (negative) constant defined in A078756.

-1, -2, -3, -4, -9, -11, -17, -82, -86, -89, -259, -1031, -1493, -3088, -18107, -3128320, -4245574, -4431505, -7141303, -25396934, -87452973, -220313229, -235578556, -1892660806, -5160802315, -5697316936, -6909396926, -17605431920, -18782195284, -19291817256

Offset

1,2

Links

Table of n, a(n) for n=1..30.

Formula

See A006784 for definition of Engel expansion

Prog

(PARI) { my(x=vector(18), a=vector(#x-1)); x[1]=-0.62923321313860758778445822033246963679442280615921;
for (i=1, #a, a[i]=ceil(1/x[i]); x[i+1]=x[i]*a[i]-1); a }

Crossrefs

Cf. A006784, A078756, A080230.

Sequence in context: A211546 A093514 A215810 * A217493 A368349 A125774

Adjacent sequences: A080228 A080229 A080230 * A080232 A080233 A080234

Keyword

sign

Author

Jon Perry, Feb 08 2003

Extensions

a(18) onward corrected by Sean A. Irvine, Sep 09 2025

Status

approved