

A218450


Number of digits of n plus number of digits of n equal to 1, 2, 4, or 8.


1



2, 2, 1, 2, 1, 1, 1, 2, 1, 3, 4, 4, 3, 4, 3, 3, 3, 4, 3, 3, 4, 4, 3, 4, 3, 3, 3, 4, 3, 2, 3, 3, 2, 3, 2, 2, 2, 3, 2, 3, 4, 4, 3, 4, 3, 3, 3, 4, 3, 2, 3, 3, 2, 3, 2, 2, 2, 3, 2, 2, 3, 3, 2, 3, 2, 2, 2, 3, 2, 2, 3, 3, 2, 3, 2, 2, 2, 3, 2, 3, 4, 4, 3, 4, 3, 3, 3
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OFFSET

1,1


LINKS

Robert Israel, Table of n, a(n) for n = 1..10000


FORMULA

lim inf a(n)/log_10 n = 1; lim sup a(n)/log_10 n = 2.


MAPLE

f:= proc(n) local L;
L:= convert(n, base, 10);
nops(L) + numboccur(L, {1, 2, 4, 8})
end proc:
map(f, [$1..100]); # Robert Israel, Apr 29 2021


MATHEMATICA

Table[d = IntegerDigits[n]; Length[d] + Count[d, 1] + Count[d, 2] + Count[d, 4] + Count[d, 8], {n, 100}] (* T. D. Noe, Nov 16 2012 *)
Table[IntegerLength[n]+Total[DigitCount[n, 10, {1, 2, 4, 8}]], {n, 100}] (* Harvey P. Dale, Aug 03 2021 *)


PROG

(PARI) a(n) = my(d = digits(n)); #d + #select(x>((x==1)  (x==2)  (x==4)  (x==8)), d); \\ Michel Marcus, Jan 31 2016


CROSSREFS

Sequence in context: A297382 A258257 A086600 * A025912 A029441 A342263
Adjacent sequences: A218447 A218448 A218449 * A218451 A218452 A218453


KEYWORD

nonn,easy,base


AUTHOR

David Williams, Oct 28 2012


STATUS

approved



