A242350 Multiply a(n-1) by 2 and drop all 0's.

1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 124, 248, 496, 992, 1984, 3968, 7936, 15872, 31744, 63488, 126976, 253952, 5794, 11588, 23176, 46352, 9274, 18548, 3796, 7592, 15184, 3368, 6736, 13472, 26944, 53888, 17776, 35552, 7114, 14228, 28456, 56912, 113824

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

Cf. A052382, A004719, A243063, A243657, A243658.

Sequence in context: A072067 A072049 A281938 * A115213 A009714 A051535

Adjacent sequences: A242347 A242348 A242349 * A242351 A242352 A242353

Keyword

nonn,base

Author

J. Lowell, May 11 2014

Extensions

More terms from Michel Marcus, May 12 2014

Status

approved