

A309721


Number of right angles between the segments that are turned "on" when representing n on a 7segment (calculator) display.


0



4, 0, 4, 4, 3, 4, 6, 1, 8, 6, 4, 0, 4, 4, 3, 4, 6, 1, 8, 6, 8, 4, 8, 8, 7, 8, 10, 5, 12, 10, 8, 4, 8, 8, 7, 8, 10, 5, 12, 10, 7, 3, 7, 7, 6, 7, 9, 4, 11, 9, 8, 4, 8, 8, 7, 8, 10, 5, 12, 10, 10, 6, 10, 10, 9, 10, 12, 7, 14, 12, 5, 1, 5, 5, 4, 5, 7, 2, 9, 7, 12, 8, 12, 12, 11, 12, 14, 9, 16, 14, 10, 6, 10, 10, 9, 10, 12, 7
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OFFSET

0,1


COMMENTS

The display is the one described in A006942 (see also the example section below).


LINKS

Table of n, a(n) for n=0..97.


FORMULA

a(n) = a(floor(n/10)) + a(n mod 10), for n > 9 (a formula by Reinhard Zumkeller, same for A006942 and A010371).


EXAMPLE

To illustrate a(0),...,a(9):
_ _ _ _ _ _ _ _
   _ _ _ _ _  _ _
_  _ _  _ _  _ _
.


MATHEMATICA

Evaluate[Table[a[n], {n, 0, 9}]]={4, 0, 4, 4, 3, 4, 6, 1, 8, 6};
a[n_/; n>9]:=a[Floor[n/10]]+a[Mod[n, 10]]; a/@Range[0, 100] (* or *)
Table[Total[IntegerDigits[n]/.{0>4, 1>0, 2>4, 3>4, 4> 3, 5>4, 7>1, 9>6}], {n, 0, 100}]


CROSSREFS

Cf. A006942, A010371, A063720, A277116.
Sequence in context: A152856 A031362 A198414 * A110854 A278086 A021716
Adjacent sequences: A309718 A309719 A309720 * A309722 A309723 A309724


KEYWORD

nonn,base,easy


AUTHOR

Ivan N. Ianakiev, Aug 14 2019


STATUS

approved



