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

Author

J. Lowell, May 11 2014

Keywords

• nonn
• base

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

Examples

			Term after 512 is 124 because 512*2=1024, and 1024 becomes 124 if all 0's are taken out.
		

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).

Crossrefs

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

Programs

Mathematica

NestList[FromDigits[Select[IntegerDigits[2 #],#!=0&]]&,1,50] (* Harvey P. Dale, Oct 22 2018 *)

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

Extensions

More terms from Michel Marcus, May 12 2014