A061587 a(1) = 1, a(n)= number obtained by replacing each digit of a(n-1) with nine times its value.

1, 9, 81, 729, 631881, 5427972729, 45361863816318631881, 36452754972542772954279725427972729, 2754364518634536816318453618636318814536186381631845361863816318631881

Offset: 1

Author

Amarnath Murthy, May 13 2001

Keywords

• nonn
• base
• easy

Comments

Each of the subsequences a(9n), a(9n-1), ..., and a(9n-8) converges to a different limit, if we consider the numbers as sequences of digits. - M. F. Hasler, Jun 24 2016

Links

• Indranil Ghosh, Table of n, a(n) for n = 1..13

Crossrefs

Cf. A061581 - A061586, A061511-A061522, A061746-A061750.

Programs

PARI

A061587(n=2,a=1,m=9)={while(n--,a=eval(concat(apply(t->Str(t),digits(a)*m))));a} \\ If only the 2nd argument is given, then the operation is applied once to that argument. - M. F. Hasler, Jun 24 2016

Extensions

More terms from Larry Reeves (larryr(AT)acm.org) and Asher Auel, May 15 2001