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A193413 Valley numbers. 4
1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 101, 111, 202, 212, 222, 303, 313, 323, 333, 404, 414, 424, 434, 444, 505, 515, 525, 535, 545, 555, 606, 616, 626, 636, 646, 656, 666, 707, 717, 727, 737, 747, 757, 767, 777, 808, 818, 828, 838, 848, 858, 868, 878, 888, 909, 919, 929, 939, 949, 959, 969, 979, 989, 999, 1001 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For n>10 the structure of digits represent a valley. The first digit is equal to the last digit (1 - 9). The first digits are in nonincreasing order. The last digits are in nondecreasing order. The numbers may have more smallest digits. Sequence is infinite.

Superset of crater numbers (A193409) and A193412.

See valley numbers in base 2 (A193414 and A193415).

LINKS

Table of n, a(n) for n=1..73.

EXAMPLE

Illustration using a member of this sequence, 6543333346:

6 . . . . . . . . 6

. 5 . . . . . . . .

. . 4 . . . . . 4 .

. . . 3 3 3 3 3 . .

CROSSREFS

Cf. A110785, A193409, A193412, A193414, A193415.

Cf. A134970. - Omar E. Pol, Aug 05 2011

Sequence in context: A276354 A084982 A110785 * A087992 A062687 A109882

Adjacent sequences:  A193410 A193411 A193412 * A193414 A193415 A193416

KEYWORD

nonn,base

AUTHOR

Jaroslav Krizek, Jul 25 2011

EXTENSIONS

More terms extended by definition by Jaroslav Krizek, Jul 27 2011

STATUS

approved

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Last modified October 14 06:58 EDT 2019. Contains 327995 sequences. (Running on oeis4.)