The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A083818 Numbers n such that 2n-1 is the digit reversal of n. 2
 1, 37, 397, 3997, 39997, 399997, 3999997, 39999997, 399999997, 3999999997, 39999999997, 399999999997, 3999999999997, 39999999999997, 399999999999997, 3999999999999997, 39999999999999997, 399999999999999997, 3999999999999999997, 39999999999999999997 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) = 1 + 36 + 360 + 3600 + 36000 + ..., for a total of n terms. a(n) = 1 + sum of first n-1 terms of the geometric progression with first term 36 and common ratio 10. a(n) = 1 + 36*A000042(n-1) (the unary sequence). LINKS Index entries for linear recurrences with constant coefficients, signature (11,-10). FORMULA a(n) = 4*10^(n-1) - 3. EXAMPLE 2*37 - 1 = 73. CROSSREFS Cf. A083811, A083812, A083813. Digit reversals are A169830. Sequence in context: A264626 A201789 A115926 * A090023 A254682 A232251 Adjacent sequences: A083815 A083816 A083817 * A083819 A083820 A083821 KEYWORD base,easy,nonn AUTHOR Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 08 2003 EXTENSIONS a(1)=1 inserted by David Radcliffe, Jul 25 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified March 22 20:34 EDT 2023. Contains 361433 sequences. (Running on oeis4.)