A038211 Can express a(n) with the digits of a(n)^4 in order, only adding plus signs.

0, 1, 7, 10, 19, 22, 25, 27, 28, 34, 36, 37, 45, 52, 54, 55, 58, 61, 63, 64, 67, 72, 73, 76, 79, 81, 82, 85, 91, 100, 103, 106, 108, 109, 112, 115, 117, 118, 121, 124, 127, 133, 135, 142, 144, 145, 148, 153, 154, 157, 162, 163, 166, 169, 172, 175, 178, 180, 181

Offset

1,3

Comments

All terms == 0, 1, 4 or 7 (mod 9). - Robert Israel, Sep 06 2020

Links

David A. Corneth, Table of n, a(n) for n = 1..10000 (first 5000 terms from Robert Israel)

Example

a(6)=22 is in the sequence because 22^4=234256 and 2+3+4+2+5+6=22.
a(8)=27 is in the sequence because 27^4=531441 and 5+3+14+4+1=27.

Maple

F:= proc(n, t) local d; option remember;
   if n = t then return true fi;
   if n < t then return false fi;
   for d from 1 to min(ilog10(t)+1, ilog10(n)+1) do
     if procname(floor(n/10^d), t - (n mod 10^d)) then return true fi
   od;
   false
end proc:
select(t -> F(t^4, t), [$0..1000]); # Robert Israel, Sep 06 2020

Crossrefs

Cf. A001477, A038206, A038209.

Sequence in context: A155027 A118420 A196939 * A122226 A240791 A064210

Adjacent sequences: A038208 A038209 A038210 * A038212 A038213 A038214

Keyword

nonn,base

Author

Erich Friedman

Extensions

Offset changed by Robert Israel, Sep 06 2020

Status

approved