The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Please make a donation to keep the OEIS running. We are now in our 56th year. In the past year we added 10000 new sequences and reached almost 9000 citations (which often say "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A309907 a(n) is the square of the number consisting of one 1 and n 3's: (133...3)^2. 3
 1, 169, 17689, 1776889, 177768889, 17777688889, 1777776888889, 177777768888889, 17777777688888889, 1777777776888888889, 177777777768888888889, 17777777777688888888889, 1777777777776888888888889, 177777777777768888888888889, 17777777777777688888888888889 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS All terms are zeroless (elements of A052382). LINKS Seiichi Manyama, Table of n, a(n) for n = 0..500 Index entries for linear recurrences with constant coefficients, signature (111,-1110,1000). FORMULA G.f.: -(40*x^2+58*x+1)/((x-1)*(100*x-1)*(10*x-1)). a(n) = A097166(n)^2 = ((4*10^n-1)/3)^2. - Seiichi Manyama, Aug 23 2019 MAPLE a:= n-> parse(cat(1, 3\$n))^2: seq(a(n), n=0..18); PROG (PARI) {a(n) = ((4*10^n-1)/3)^2} \\ Seiichi Manyama, Aug 23 2019 CROSSREFS Cf. A052382, A097166, A102807. Sequence in context: A264276 A231769 A069297 * A264222 A051477 A227692 Adjacent sequences:  A309904 A309905 A309906 * A309908 A309909 A309910 KEYWORD nonn,base,easy AUTHOR Alois P. Heinz, Aug 21 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 2 23:36 EST 2020. Contains 338898 sequences. (Running on oeis4.)