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

Author

Erich Friedman

Keywords

• nonn
• base

Comments

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

Examples

			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.
		

Links

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

Crossrefs

Cf. A001477, A038206, A038209.

Programs

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

Extensions

Offset changed by Robert Israel, Sep 06 2020