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A242350 Multiply a(n-1) by 2 and drop all 0's. 8
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 20 06:56 EDT 2021. Contains 345157 sequences. (Running on oeis4.)