OFFSET
1,2
COMMENTS
Sequence enters a loop having period 36 at index 491: a(491) = a(527) = 366784, min and max being 28714 and 11772544. Starting with 3 instead of 1 gives another cycle. - Tom Edgar and Michel Marcus, May 13 2014
Zeroless analog of powers of 2. - N. J. A. Sloane, Jun 11 2014
LINKS
Michel Marcus, Table of n, a(n) for n = 1..600
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1).
EXAMPLE
Term after 512 is 124 because 512*2=1024, and 1024 becomes 124 if all 0's are taken out.
MATHEMATICA
NestList[FromDigits[Select[IntegerDigits[2 #], #!=0&]]&, 1, 50] (* Harvey P. Dale, Oct 22 2018 *)
PROG
(PARI) dropz(n)=d = digits(n); s = 0; for (i=1, #d, if (d[i], s = 10*s + d[i]); ); s;
lista(nn) = a = 1; for (i=1, nn, print1(a, ", "); a = dropz(2*a); ) \\ Michel Marcus, May 12 2014
CROSSREFS
KEYWORD
nonn,base
AUTHOR
J. Lowell, May 11 2014
EXTENSIONS
More terms from Michel Marcus, May 12 2014
STATUS
approved