

A305238


Negative numbers in base 10.


4



19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 79, 78, 77, 76, 75
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OFFSET

1,1


COMMENTS

a(n) = A039723(n).
Also base 10 representation of n reinterpreted as decimal numbers.
The first comment is slightly misleading because sequence A039723 isn't defined for n < 0, and none of the terms a(n) here is a term of A039723. However, it can be seen as the definition of the extension of A039723 to negative indices. Also, the (naïve) recursive definition or implementation of A039723 requires that function to be defined for negative arguments, and using the generic formula it will work as expected for n, n > 0.  M. F. Hasler, Oct 16 2018


LINKS

Jianing Song, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Negadecimal
Eric Weisstein's World of Mathematics, Negabinary
Wikipedia, Negative base


EXAMPLE

1 in base 10 is represented as 19 (1*(10) + 9 = 1), so a(1) = 19;
11 in base 10 is represented as 29 (2*(10) + 9 = 11), so a(11) = 29;
99 in base 10 is represented as 1901 (1*(10)^3 + 9*(10)^2 + 1 = 99), so a(99) = 1901.


PROG

(PARI) A305238(n)=A039723(n) \\ M. F. Hasler, Oct 16 2018


CROSSREFS

Cf. A039724 (nonnegative numbers in base 2), A212529 (negative numbers in base 2), A007608 (nonnegative numbers in base 4), A212526 (negative numbers in base 4), A039723 (nonnegative numbers in base 10).
Sequence in context: A230339 A022975 A023461 * A004460 A082126 A176411
Adjacent sequences: A305235 A305236 A305237 * A305239 A305240 A305241


KEYWORD

nonn,base,easy


AUTHOR

Jianing Song, Jun 19 2018


STATUS

approved



