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A056525 Palindromes with odd number of digits. 4
1, 2, 3, 4, 5, 6, 7, 8, 9, 101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 202, 212, 222, 232, 242, 252, 262, 272, 282, 292, 303, 313, 323, 333, 343, 353, 363, 373, 383, 393, 404, 414, 424, 434, 444, 454, 464, 474, 484, 494, 505, 515, 525, 535, 545, 555, 565 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Concatenation of all but final digits of n with reverse of n (keeping leading zeros in the reverse)

A178788(a(n)) = 0 for n > 9. [From Reinhard Zumkeller, Jun 30 2010]

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Index entries for sequences related to final digits of numbers

FORMULA

a(n) = floor[n/10]*10^A055642(n)+A004086(n)

MATHEMATICA

Join[Range[9], Table[FromDigits[Join[x=IntegerDigits[n], Reverse[Drop[x, -1]]]], {n, 10, 56}]] (* Jayanta Basu, May 29 2013 *)

PROG

(Haskell)

a056525 n = a056525_list !! (n-1)

a056525_list = [1..9] ++ [read (ns ++ [z] ++ reverse ns) |

                n <- [1..], let ns = show n, z <- "0123456789"]

-- Reinhard Zumkeller, Dec 28 2011

CROSSREFS

Cf. A002113, A004086, A056524.

Sequence in context: A052426 A240237 A056142 * A071272 A083851 A071275

Adjacent sequences:  A056522 A056523 A056524 * A056526 A056527 A056528

KEYWORD

base,easy,nonn

AUTHOR

Henry Bottomley, Jun 16 2000

STATUS

approved

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Last modified October 21 08:47 EDT 2019. Contains 328292 sequences. (Running on oeis4.)