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A121167
a(1)=1; a(n) = the reversal of (a(n-1) + spd(a(n-1))), where spd(n) is the sum of d^d for d the digits of n (with 0^0 = 1).
1
1, 2, 6, 26664, 298661, 386985404, 646010808, 218856976, 288157046, 460585223, 736514774, 427530937, 259106618, 767004366, 507197867, 489519319, 2141658661, 3329758512, 3706874373, 2129616273, 8563597152, 3644768698, 9667076604
OFFSET
1,2
COMMENTS
Eventually periodic with period 7978, as a(23895) = a(31873) = 3365361711. - Robert Israel, Oct 13 2024
LINKS
MAPLE
f(0):= 1: for i from 1 to 9 do f(i):= i^i od:
rev:= proc(n) local L, i;
L:= convert(n, base, 10);
add(L[-i]*10^(i-1), i=1..nops(L))
end proc:
R:= 1: x:= 1:
for n from 1 to 25 do
x:= rev(x + convert(map(f, convert(x, base, 10)), `+`));
R:= R, x
od:
R; # Robert Israel, Oct 13 2024
MATHEMATICA
s={1}; fn[n_]:=If[n>0, n^n, 1]; Do[AppendTo[s, IntegerReverse[Total[fn/@IntegerDigits[s[[-1]]]]+s[[-1]]]], {n, 22}]; s (* James C. McMahon, Oct 13 2024 *)
CROSSREFS
Cf. A045503 (spd).
Sequence in context: A162146 A231545 A055698 * A115658 A337096 A005607
KEYWORD
base,easy,nonn,look
AUTHOR
Jason Earls, Aug 14 2006
EXTENSIONS
Name clarified by Robert Israel, Oct 13 2024
STATUS
approved