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A088180 a(n) is the number of numbers m < 10^n for which there is at least one k such that k + reverse(k) = m. 1
1, 5, 19, 112, 368, 2161, 7033, 41140, 133730, 781884, 2541197, 14856466, 48283738, 282274893, 917394087, 5363229225, 17430497086, 101901374524, 331179473681, 1936126175213, 6292410089388, 36786397511512, 119555791973835, 698941553280624, 2271560048351176 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Number of terms of A067030 below 10^n.

a(16)-a(18) are based on two empirically detected recursive formulas. [Lars Blomberg, Nov 25 2011]

LINKS

Hiroaki Yamanouchi, Table of n, a(n) for n = 0..100

Lars Blomberg, A short investigation of the sequence and derivation of the recursive formulas

Index entries for sequences related to Reverse and Add!

EXAMPLE

a(1) = 5 since 0, 2, 4, 6, 8 are the terms of A067030 which are smaller than 10^1.

CROSSREFS

Cf. A067030.

Sequence in context: A071828 A280067 A158615 * A206709 A199480 A209111

Adjacent sequences:  A088177 A088178 A088179 * A088181 A088182 A088183

KEYWORD

nonn,base

AUTHOR

Klaus Brockhaus, Sep 22 2003

EXTENSIONS

a(9)-a(10) from Donovan Johnson, Sep 22 2009

a(11)-a(18) from Lars Blomberg, Dec 19 2011

a(19)-a(24) from Hiroaki Yamanouchi, Sep 04 2014

STATUS

approved

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Last modified January 20 17:47 EST 2018. Contains 297961 sequences.