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A266139 Volcano palindromes: palindromes not in A110784 such that removing one digit will result in a term in A110784. 2
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 101, 202, 212, 303, 313, 323, 404, 414, 424, 434, 505, 515, 525, 535, 545, 606, 616, 626, 636, 646, 656, 707, 717, 727, 737, 747, 757, 767, 808, 818, 828, 838, 848, 858, 868, 878, 909, 919, 929, 939, 949, 959, 969, 979, 989, 11011 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

All terms have odd number of digits. Terms are palindromes such that digits are nondecreasing halfway through except for the middle digit, which is strictly smaller that its neighboring digits.

Illustration using a member of this sequence, 23446564432:

.  .  .  .  6  .  6  .  .  .  .

.  .  .  .  .  5  .  .  .  .  .

.  .  4  4  .  .  .  4  4  .  .

.  3  .  .  .  .  .  .  .  3  .

2  .  .  .  .  .  .  .  .  .  2

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000

CROSSREFS

Cf. A110784.

Sequence in context: A030147 A207954 A193412 * A154562 A193409 A280823

Adjacent sequences:  A266136 A266137 A266138 * A266140 A266141 A266142

KEYWORD

nonn,easy,base

AUTHOR

Chai Wah Wu, Dec 25 2015

STATUS

approved

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Last modified November 13 08:18 EST 2019. Contains 329093 sequences. (Running on oeis4.)