A135696 - OEIS

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A135696

Palindromes with odd number of digits formed from the reflected decimal expansion of e.

2, 272, 27172, 2718172, 271828172, 27182828172, 2718281828172, 271828181828172, 27182818281828172, 2718281828281828172, 271828182848281828172, 27182818284548281828172, 2718281828459548281828172, 271828182845909548281828172, 27182818284590409548281828172

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

e = 2.71828182845904523536028747135... (see A001113).

The number of digits of a(n) is equal to 2n-1.

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..250

EXAMPLE

n ............ a(n)

1 ............. 2

2 ............ 272

3 ........... 27172

4 .......... 2718172

5 ......... 271828172

6 ........ 27182828172

7 ....... 2718281828172

8 ...... 271828181828172

9 ..... 27182818281828172

10 ... 2718281828281828172

MATHEMATICA

nn=20; With[{ed=RealDigits[E, 10, nn][[1]]}, Table[FromDigits[Join[Take[ ed, n], Reverse[Take[ed, n-1]]]], {n, nn}]] (* Harvey P. Dale, Sep 10 2012 *)

CROSSREFS

Cf. A001113, A002113.

Sequence in context: A324596 A007512 A048534 * A008775 A237993 A174710

Adjacent sequences: A135693 A135694 A135695 * A135697 A135698 A135699

KEYWORD

base,nonn

AUTHOR

Omar E. Pol, Mar 01 2008, corrected Mar 02 2008

EXTENSIONS

More terms from Harvey P. Dale, Sep 10 2012

STATUS

approved