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A331218
a(n) is the numbers of ways to write n = u + v where the decimal representations of u and of v have the same number of digits d for d = 0..9.
3
1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 3, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 4, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 5, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 6, 1, 0, 1, 0, 1, 0, 1, 0, 1
OFFSET
0,34
COMMENTS
In other words, a(n) is the number of ways to write n as the sum of two anagrams.
Leading zeros are ignored.
LINKS
Rémy Sigrist, Scatterplot of (x, y) such that 0 <= x, y <= 10^3 and x and y are decimal anagrams (a(n) corresponds to the number of pixels (x, y) such that x+y = n)
EXAMPLE
For n = 44:
- we have the following ways to write 44 as a sum of two anagrams:
u v
-- --
13 31
22 22
31 13
- hence a(44) = 3.
PROG
(PARI) See Links section.
CROSSREFS
Cf. A330827 (ternary analog), A331216 (binary analog).
Sequence in context: A247477 A072927 A307194 * A120086 A215030 A175816
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Jan 12 2020
STATUS
approved