OFFSET
0,1
COMMENTS
Each term of this sequence includes 4, the number of raised dots to represent the numeral sign. This is normally necessary since the representations of the numerals "1" through "9" and then "0" are otherwise identical to the representations of the letters "a" through "j", respectively. In some contexts the numeral sign is unnecessary.
LINKS
Indranil Ghosh, Table of n, a(n) for n = 0..50000
RNIB, This is Braille
FORMULA
The decimal digits map to numbers of Braille raised dots as follows: 0 -> 3, 1 -> 1, 2 -> 2, 3 -> 2, 4 -> 3, 5 -> 2, 6 -> 3, 7 -> 4, 8 -> 3 and 9 -> 2.
EXAMPLE
a(10) = 8 because "10" is represented by the numeral sign "#" (4 raised dots), the digit one (1 raised dot) and digit zero (3 raised dots) and 4 + 3 + 1 = 8. Here is a depiction of the Braille representation, where "o" denotes a raised dot, "-" denotes unused space and each Braille character occupies a 3 X 2 cell:
-o o- -o
-o -- oo
oo -- --
PROG
(Python)
B=[3, 1, 2, 2, 3, 2, 3, 4, 3, 2]
def A072283(n):
....s=0
....for i in str(n):
........s+=B[int(i)]
....return s+4 # Indranil Ghosh, Jan 13 2017
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Rick L. Shepherd, Jul 10 2002
STATUS
approved