A121761 In decimal number system, take negative power of 10 at even digits of n. Sequence gives numerators of result.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1, 6, 11, 16, 21, 26, 31, 36, 41, 46, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 2, 7, 12, 17, 22, 27, 32, 37, 42, 47, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 3, 8, 13, 18, 23, 28, 33, 38, 43, 48, 70, 71, 72, 73, 74, 75

Offset

1,2

Comments

See accompanying sequence A121760 In decimal number system, take negative power of 10 at odd digits of n.

Links

Zak Seidov, First 1000 terms

Formula

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

Example

a(23)=16 because 23=2*10^1+3*10^0 and a(23)=numerator[2*10^((-1)^(1+2)*1)+3*10^((-1)^(1+3)*0)=2/10+3=32/10=16/5]=16.

Crossrefs

Cf. A121760.

Sequence in context: A106620 A080685 A074805 * A056963 A291769 A167129

Adjacent sequences: A121758 A121759 A121760 * A121762 A121763 A121764

Keyword

base,frac,nonn

Author

Zak Seidov, Aug 20 2006

Status

approved