1,2

Also, numbers simultaneously octagonal and centered octagonal. - Steven Schlicker (schlicks(AT)gvsu.edu), Apr 24 2007

S. Schlicker, Numbers Simultaneously Polygonal and Centered Polygonal, submitted.

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Let x(n) + y(n)*sqrt(48) = (8+sqrt(48))*(7+sqrt(48))^n, s(n) = (y(n)+1)/2; then a(n) = (1/2)*(2+8*(s(n)^2-s(n))) - Steven Schlicker (schlicks(AT)gvsu.edu), Apr 24 2007

a(n+2)=194*a(n+1)-a(n)+32 and also a(n+1)=97*a(n)+56*(3*a(n)^2+a(n))^0.5. - Richard Choulet, Sep 26 2007

G.f.: x(x^2+30x+1)/[(1-x)(1-194x+x^2)].

CP := n -> 1+1/2*8*(n^2-n): N:=10: u:=7: v:=1: x:=8: y:=1: k_pcp:=[1]: for i from 1 to N do tempx:=x; tempy:=y; x:=tempx*u+48*tempy*v: y:=tempx*v+tempy*u: s:=(y+1)/2: k_pcp:=[op(k_pcp), CP(s)]: end do: k_pcp; - Steven Schlicker (schlicks(AT)gvsu.edu), Apr 24 2007

Cf. A000567, A016754.

Cf. A006060, A006051, A028230, A046184.

Sequence in context: A110204 A051364 A061051 this_sequence A109688 A013757 A077729

Adjacent sequences: A036425 A036426 A036427 this_sequence A036429 A036430 A036431

nonn,easy

Jean-Francois Chariot (jean-francois.chariot(AT)afoc.alcatel.fr)

More terms from Eric Weisstein (eric(AT)weisstein.com)

Edited by njas, Oct 02 2007