A074458 - OEIS

A074458

Number of segments lit to display the number n on a 7-segment display (as in pocket calculators): variant where '6', '7' and '9' use 6, 4 resp. 5 segments.

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

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OFFSET

0,1

COMMENTS

Sequences A234691 and A234692 use one bit for each lit segment. See crossrefs for other variants. - M. F. Hasler, Jun 17 2020

LINKS

Table of n, a(n) for n=0..78.

Index entries for sequences related to calculator display

FORMULA

From M. F. Hasler, Jun 17 2020: (Start)

a(n) = a(n mod 10) + a(floor(n/10)) for n > 9.

a(n) = A006942(n) - A102679(n) + A102681(n). (End)

EXAMPLE

LED display:

_ _ _ _ _ _ _ _

| | | _| _| |_| |_ |_ | | |_| |_|

|_| | |_ _| | _| |_| | |_| |

so we have a(0) = 6, a(1) = 2, a(2) = 5 ...

PROG

(PARI) apply( {A074458(n)=digits(6255456475)[n%10+1]+if(n>9, self()(n\10))}, [0..99]) \\ M. F. Hasler, Jun 17 2020

CROSSREFS

Cf. A074459.

For other versions of this sequence, see A006942 (7 with one segment less), A063720 (6 and 7 with one segment less), A010371 (9 with one segment more), A277116 (7 with one segment less, 9 with one segment more).

Cf. A234691, A234692, A000120.

Sequence in context: A063720 A277116 A006942 * A010371 A270614 A011489

Adjacent sequences: A074455 A074456 A074457 * A074459 A074460 A074461

KEYWORD

nonn,base

AUTHOR

Y. Kelly Itakura (yitkr(AT)mta.ca), Aug 22 2002

EXTENSIONS

Example edited by Jon E. Schoenfield, Jul 30 2017

Edited and extended to n > 9 by M. F. Hasler, Jun 17 2020

STATUS

approved