A246422 Numbers in which cubes may end (in base 10).

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 16, 17, 19, 21, 23, 24, 25, 27, 28, 29, 31, 32, 33, 36, 37, 39, 41, 43, 44, 47, 48, 49, 51, 52, 53, 56, 57, 59, 61, 63, 64, 67, 68, 69, 71, 72, 73, 75, 76, 77, 79, 81, 83, 84, 87, 88, 89, 91, 92, 93, 96, 97, 99, 101, 103, 104, 107, 109, 111, 112, 113, 117

Offset

1,3

Links

Ivan Neretin, Table of n, a(n) for n = 1..5065

Example

33 is a member because 77^3 = 456533 is a cube ending in 33.

Mathematica

Union@Flatten@Table[Mod[i^3, 10^n], {n, 3}, {i, 10^n}] (* Ivan Neretin, Aug 30 2015*)

Prog

(PARI)
v=[]; for(k=1, 10^3, for(m=1, 3, v=concat(v, k^3%10^m)); vecsort(v, , 8); v
(PARI)
a=[]; for(m=1, 3, a=setunion(a, Set(vector(10^m, n, n^3)%10^m))); a
(Python)
from itertools import count, islice
from sympy import nthroot_mod
def A246422_gen(startvalue=0): # generator of terms >= startvalue
    return filter(lambda n:len(nthroot_mod(n, 3, 10**(len(str(n))))), count(max(startvalue, 0)))
A246422_list = list(islice(A246422_gen(), 20)) # Chai Wah Wu, Feb 16 2023

Crossrefs

Cf. A238712, A246449.

Sequence in context: A081061 A317589 A141807 * A072495 A257671 A285523

Adjacent sequences: A246419 A246420 A246421 * A246423 A246424 A246425

Keyword

nonn,base

Author

Derek Orr, Aug 25 2014

Extensions

Corrected by Ivan Neretin, Mar 03 2016

Status

approved