A069494 Numbers n such that (reversal(n))^3 = reversal(n^3). Ignore leading 0's.

0, 1, 2, 7, 10, 11, 20, 70, 100, 101, 110, 111, 200, 700, 1000, 1001, 1010, 1011, 1100, 1101, 1110, 2000, 7000, 10000, 10001, 10010, 10011, 10100, 10101, 10110, 11000, 11001, 11010, 11011, 11100, 20000, 70000, 100000, 100001, 100010, 100011, 100100, 100101

Offset

1,3

Comments

For an arithmetical function f, call the arguments n such that f(reverse(n)) = reverse(f(n)) the "palinpoints" of f. This sequence is the sequence of palinpoints of f(n) = n^3.

Links

Table of n, a(n) for n=1..43.

Example

Let f(n) = n^3. Then f(1011) = 1033364331, f(1101) = 1334633301, so f(reverse(1011)) = reverse(f(1011)). Therefore 1011 belongs to the sequence.

Maple

r:= n-> (s-> parse(cat(seq(s[-i], i=1..length(s)))))(""||n):
q:= n-> is(r(n^3)=r(n)^3):
select(q, [$0..200000])[];  # Alois P. Heinz, Oct 22 2021

Mathematica

rev[n_] := FromDigits[Reverse[IntegerDigits[n]]]; f[n_] := n^3; Select[Range[10^5], f[rev[ # ]] == rev[f[ # ]] &]

Crossrefs

Cf. A000578, A004086, A085315.

Sequence in context: A050596 A045266 A108493 * A134712 A030344 A190433

Adjacent sequences: A069491 A069492 A069493 * A069495 A069496 A069497

Keyword

nonn,base

Author

Joseph L. Pe, Apr 15 2002

Extensions

More terms from Alois P. Heinz, Oct 22 2021

Status

approved