

A063720


Number of segments lit in a 7segment display (as on a calculator) to represent the number n, variant 0: '6', '7' and '9' use 5, 3 and 5 segments, respectively.


19



6, 2, 5, 5, 4, 5, 5, 3, 7, 5, 8, 4, 7, 7, 6, 7, 7, 5, 9, 7, 11, 7, 10, 10, 9, 10, 10, 8, 12, 10, 11, 7, 10, 10, 9, 10, 10, 8, 12, 10, 10, 6, 9, 9, 8, 9, 9, 7, 11, 9, 11, 7, 10, 10, 9, 10, 10, 8, 12, 10, 11, 7, 10, 10, 9, 10, 10, 8, 12, 10, 9, 5, 8, 8, 7, 8, 8, 6, 10, 8, 13, 9, 12, 12, 11, 12
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OFFSET

0,1


COMMENTS

If we mark with * resp. ' the glyph variants (graphical representations) which use more resp. less segments, we have the following variants:
A063720 (this: 6', 7', 9'), A277116 (6*, 7', 9'), A074458 (6*, 7*, 9'), ___________________________ A006942 (6*, 7', 9*), A010371 (6*, 7*, 9*). Sequences A234691, A234692 and variants make precise which segments are lit in each digit. These are related through the Hamming weight function A000120, e.g., A010371(n) = A000120(A234691(n)) = A000120(A234692(n)).  M. F. Hasler, Jun 17 2020


LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
Index entries for sequences related to calculator display


FORMULA

a(n) = a(floor(n/10)) + a(n mod 10) for n > 9.  Reinhard Zumkeller, Mar 15 2013
a(n) <= A277116(n) <= min{A006942(n), A074458(n)} <= A010371(n); differences between these are given, e.g., by A102677(n)  A102679(n) (= number of digits 7 in n).  M. F. Hasler, Jun 17 2020


EXAMPLE

The number 8 on a digital readout (e.g., on a calculator display) can be represented as

 

 

which uses all 7 segments. Therefore a(8) = 7.
From M. F. Hasler, Jun 17 2020: (Start)
This sequence uses the following representations:
_ _ _ _ _ _ _
   _ _ _ _ _  _ _
_  _ _  _ _  _ 
.
See crossrefs for other variants. (End)


MATHEMATICA

a[n_ /; n <= 9] := a[n] = {6, 2, 5, 5, 4, 5, 5, 3, 7, 5}[[n+1]]; a[n_] := a[n] = a[Quotient[n, 10]] + a[Mod[n, 10]]; Table[a[n], {n, 0, 85}] (* JeanFrançois Alcover, Aug 12 2013, after Reinhard Zumkeller *)
Table[Total[IntegerDigits[n]/.{0>6, 1>2, 2>5, 3>5, 6>5, 7>3, 8>7, 9>5}], {n, 0, 90}] (* Harvey P. Dale, Mar 27 2021 *)


PROG

(Haskell)
a063720 n = a063720_list !! n
a063720_list = [6, 2, 5, 5, 4, 5, 5, 3, 7, 5] ++ f 10 where
f x = (a063720 x' + a063720 d) : f (x + 1)
where (x', d) = divMod x 10
 Reinhard Zumkeller, Mar 15 2013
(PARI) apply( {A063720(n)=digits(6255455375)[n%10+1]+if(n>9, self()(n\10))}, [0..99]) \\ M. F. Hasler, Jun 17 2020


CROSSREFS

For variants see A006942, A010371, A074458, A277116 (cf. comments).
Other related sequences: A018846, A018847, A018849, A038136, A053701.
Sequence in context: A124457 A258102 A309449 * A277116 A006942 A074458
Adjacent sequences: A063717 A063718 A063719 * A063721 A063722 A063723


KEYWORD

nonn,base,nice


AUTHOR

Deepan Majmudar (deepan.majmudar(AT)compaq.com), Aug 23 2001


EXTENSIONS

More terms from Matthew Conroy, Sep 13 2001
Definition clarified by M. F. Hasler, Jun 17 2020


STATUS

approved



