OFFSET
1,2
COMMENTS
The term 0 is included by convention (we consider here that it has no digit).
Each term has an even number of digits, and each digit has an even number of occurrences; hence each term belongs to A283871.
This sequence has connections with A014486; in both sequences digits are balanced in some way.
All palindromes with even number of digits belong to this sequence.
LINKS
Rémy Sigrist, Table of n, a(n) for n = 1..4159 (terms < 10^6)
FORMULA
11 | a(n). - David A. Corneth, Mar 07 2021
EXAMPLE
The digits of 5586557768 can be paired as follows:
(55)(8(6(55)(77)6)8)
so 5586557768 belongs to this sequence.
PROG
(PARI) is(n, base=10) = { my (u=0, s=0); while (n, my (d=n%base); if (u && s%base==d, u--; s\=base, u++; s=s*base+d); n\=base); u==0 }
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Mar 21 2020
STATUS
approved