A061835 a(1) = 5; a(n) = smallest power of 5 (larger than a(n-1)) with a(n-1) forming its final digits.

5, 25, 125, 3125, 1953125, 45474735088646411895751953125

Offset

1,1

Comments

a(7) > 5^50000. - Klaus Brockhaus, Jun 03 2001

a(7) = 5^134217769. - Sean A. Irvine, Mar 06 2023

Links

Table of n, a(n) for n=1..6.

Index entries for sequences related to final digits of numbers

Example

After 3125 = 5^5 the next term is 1953125 = 5^9, containing 3125 as its final digits.

Prog

(ARIBAS) a := 5; n := 1; writeln("a(", n, ") = ", a); stop := 50000; run := true; c := 1; while run do b := a; len := length(itoa(b)); inc(n); a := 1; while a mod 10^len <> b and c <> stop do inc(c); a := 5^c; end; if c < stop then writeln("a(", n, ") = ", 5, "^", c, " = ", a); else writeln("a(", n, ") > ", 5, "^", c); run := false; end; end;

Crossrefs

Sequence in context: A062875 A140288 A306570 * A321288 A030988 A173260

Adjacent sequences: A061832 A061833 A061834 * A061836 A061837 A061838

Keyword

nonn,base

Author

Amarnath Murthy, May 29 2001

Extensions

Description corrected by and one more term from Klaus Brockhaus, Jun 03 2001

a(6) also found by Frank Ellermann, Jun 04 2001

Status

approved