The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A218450 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A218450

Number of digits of n plus number of digits of n equal to 1, 2, 4, or 8.
(history; published version)

#22 by Harvey P. Dale at Tue Aug 03 20:23:28 EDT 2021

STATUS

editing

approved

#21 by Harvey P. Dale at Tue Aug 03 20:23:25 EDT 2021

MATHEMATICA

Table[IntegerLength[n]+Total[DigitCount[n, 10, {1, 2, 4, 8}]], {n, 100}] (* Harvey P. Dale, Aug 03 2021 *)

STATUS

approved

editing

#20 by Michel Marcus at Fri Apr 30 06:31:16 EDT 2021

STATUS

reviewed

approved

#19 by Joerg Arndt at Fri Apr 30 03:06:28 EDT 2021

STATUS

proposed

reviewed

#18 by Robert Israel at Thu Apr 29 15:44:29 EDT 2021

STATUS

editing

proposed

#17 by Robert Israel at Thu Apr 29 15:40:56 EDT 2021

MAPLE

end proc:

end proc:map(f, [$1..100]); # Robert Israel, Apr 29 2021

#16 by Robert Israel at Thu Apr 29 15:40:40 EDT 2021

LINKS

Robert Israel, <a href="/A218450/b218450.txt">Table of n, a(n) for n = 1..10000</a>

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

STATUS

approved

editing

#15 by Joerg Arndt at Sun Jan 31 03:30:26 EST 2016

STATUS

proposed

approved

#14 by Michel Marcus at Sun Jan 31 03:06:30 EST 2016

STATUS

editing

proposed

#13 by Michel Marcus at Sun Jan 31 03:06:25 EST 2016

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

STATUS

approved

editing