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A063585
Least k >= 0 such that 5^k has exactly n 0's in its decimal representation.
10
0, 8, 13, 34, 40, 48, 52, 45, 64, 99, 143, 132, 100, 122, 117, 151, 205, 207, 201, 242, 230, 244, 231, 221, 295, 264, 266, 333, 248, 344, 346, 274, 391, 345, 356, 393, 433, 365, 472, 499, 488, 455, 516, 485, 511, 458, 520, 487, 459, 456, 457
OFFSET
0,2
LINKS
M. F. Hasler, Zeroless powers. OEIS Wiki, March 2014
MAPLE
N:= 100: # to get a(0)..a(N)
A:= Array(0..N, -1):
p:= 1: A[0]:= 0:
count:= 1:
for k from 1 while count <= N do
p:= 5*p;
m:= numboccur(0, convert(p, base, 10));
if m <= N and A[m] < 0 then A[m]:= k; count:= count+1;
od:
convert(A, list); # Robert Israel, Dec 20 2018
MATHEMATICA
a = {}; Do[k = 0; While[ Count[ IntegerDigits[5^k], 0] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a
PROG
(PARI) A063585(n)=for(k=n, oo, #select(d->!d, digits(5^k))==n&&return(k)) \\ M. F. Hasler, Jun 14 2018
CROSSREFS
Cf. A031146 (analog for 2^k), A063555 (analog for 3^k), A063575 (analog for 4^k), A063596 (analog for 6^k).
Sequence in context: A321483 A096371 A354595 * A258768 A048851 A375786
KEYWORD
base,nonn
AUTHOR
Robert G. Wilson v, Aug 10 2001
EXTENSIONS
a(0) changed to 0 (as in A031146, A063555, ...) and better title from M. F. Hasler, Jun 14 2018
STATUS
approved