A175422 Sequence of numbers after 3rd step of iteration defined in A175419.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 4, 9, 6, 25, 36, 1, 1, 1, 0, 1, 8, 6561, 1, 25, 216, 1, 8, 1, 0, 1, 6, 1, 1, 1, 1, 1, 1, 1, 0, 1, 8, 1, 1, 867361737988403547205962240695953369140625, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1

Offset

0,3

Links

Table of n, a(n) for n=0..69.

Example

For n = 33: a(33) = 6561 because for the number 33 there are 4 steps of defined iteration: {3^3 = 27}, {7^2 = 49}, {9^4 = 6561}, {((1^6)^5)^6 = 1} and the 3rd step of the iteration ends with 6561.

Maple

A175420 := proc(n) option remember; local dgs, a, i ; if n = 0 then return 0 ; end if; dgs := convert(n, base, 10) ; a := op(1, dgs) ; for i from 2 to nops(dgs) do a := a^ op(i, dgs) ; end do: a ; end proc:
A175421 := proc(n) A175420(A175420(n)) ; end proc:
A175422 := proc(n) A175420(A175421(n)) ; end proc:
for n from 0 do printf("%d, \n", A175422(n)) ; end do; # R. J. Mathar, May 12 2010

Mathematica

Unprotect[Power]; Power[0, 0] = 1; Protect[Power]; A175420[0]=0; A175420[n_]:=If[(len=IntegerLength[n])==1, n, Last[list=IntegerDigits[n]]^Product[Part[Drop[list, -1], i], {i, len-1}]]; a[n_]:=Nest[A175420[#]&, n, 3]; Array[a, 70, 0] (* Stefano Spezia, Feb 25 2024 *)

Crossrefs

Cf. A175419, A175420, A175421, A175423, A175424, A175425, A175426, A175427.

Sequence in context: A179636 A217657 A175419 * A175423 A175421 A175420

Adjacent sequences: A175419 A175420 A175421 * A175423 A175424 A175425

Keyword

nonn,base

Author

Jaroslav Krizek, May 09 2010

Extensions

7 more terms from R. J. Mathar, May 12 2010

Status

approved