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A061835
a(1) = 5; a(n) = smallest power of 5 (larger than a(n-1)) with a(n-1) forming its final digits.
0
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
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
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