A007704 - OEIS

A007704

a(n+2) = (a(n) - 1)*a(n+1) + 1.
(Formerly M0594)

2, 3, 4, 9, 28, 225, 6076, 1361025, 8268226876, 11253255215681025, 93044467205527772332546876, 1047053135870867396062743192203958743681025

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

J. L. Davison and Jeffrey O. Shallit, Continued Fractions for Some Alternating Series, Monatshefte für Mathematik, Vol. 111 (1991), pp. 119-126; alternative link.

FORMULA

a(n) = A006277(n) + 1. - R. J. Mathar, Apr 27 2007

Product_{k=1..n} a(k) = A006277(k)*A006277(k+1). - Amiram Eldar, Mar 19 2024

MAPLE

A007704 := proc(n) options remember; if n <= 2 then RETURN(n+1) else (A007704(n-2)-1)*A007704(n-1)+1; fi; end;

MATHEMATICA

RecurrenceTable[{a[n] == a[n-1] (a[n-2] - 1) + 1, a[1] == 2, a[2] == 3}, a, {n, 1, 12}] (* Jean-François Alcover, Apr 05 2020 *)

CROSSREFS

KEYWORD

nonn,easy

AUTHOR

STATUS

approved