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Search: id:A121759
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A121759 In decimal number system, take even digits of n with negative sign. +0
3
1, -2, 3, -4, 5, -6, 7, -8, 9, 10, 11, 8, 13, 6, 15, 4, 17, 2, 19, -20, -19, -22, -17, -24, -15, -26, -13, -28, -11, 30, 31, 28, 33, 26, 35, 24, 37, 22, 39, -40, -39, -42, -37, -44, -35, -46, -33, -48, -31, 50, 51, 48, 53, 46, 55, 44, 57, 42, 59, -60, -59, -62, -57, -64, -55, -66, -53, -68, -51, 70, 71, 68, 73, 66, 75, 64, 77, 62 (list; graph; listen)
OFFSET

1,2

COMMENT

See A121758. In decimal number system, take odd digits of n with negative sign.

a(A014261(n)) = A014261(n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 30 2007

FORMULA

If n = d(i)*10^(i-1), then a(n)=(-1)^(1+d(i))*d(i)*10^(i-1). a(n)=-A121759(n)

EXAMPLE

a(12)=8 because 12=1*10^1+2*10^0 and a(12)=(-1)^(1+1)*1*10^1+(-1)^(1+2)*2*10^0=10-2=8.

CROSSREFS

Cf. A121758.

Sequence in context: A043271 A062759 A121758 this_sequence A072778 A034326 A053833

Adjacent sequences: A121756 A121757 A121758 this_sequence A121760 A121761 A121762

KEYWORD

base,sign,nice

AUTHOR

Zak Seidov (zakseidov(AT)yahoo.com), Aug 20 2006

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Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.


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