A269241 Number of times the digit 1 appears in the decimal expansion of n^3.

0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 2, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 2, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 2, 0, 1, 2, 2, 1, 2, 1, 1, 1, 1, 2, 2, 3, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 2, 0, 1, 0, 1, 0, 0, 0, 0, 1, 2, 1, 1, 0, 2, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0

Offset

0,12

Comments

The cubes corresponding to the first occurrence of 1, 2, 3, ... are listed in A036528, i.e., A036528(n)^(1/3) = A048366(n) is the index of the first occurrence of n.

Links

Table of n, a(n) for n=0..95.

Example

0^3 = 0 has a(0) = 0 digits '1'.
1^3 = 1 has a(1) = 1 digit '1'.
2^3 = 8 has a(2) = 0 digits '1'.
3^3 = 27 has a(3) = 0 digits '1'.
4^3 = 64 has a(4) = 0 digits '1'.
5^3 = 125 has a(5) = 1 digit '1'.
11^3 = 1331 is the smallest cube to have a(11) = 2 digits '1'.

Mathematica

Table[DigitCount[n^3, 10, 1], {n, 0, 99}] (* Alonso del Arte, Feb 20 2016 *)

Prog

(PARI) A269241(n)=#select(t->t==1, digits(n^3))

Crossrefs

Cf. A036528 and A036527 - A036536; A048366 and A048365 - A048374.

Analog for the other digits 0, 2, ..., 9: A269250, A269242, A269243, A269244, A269245, A269246, A269247, A269248, A269249.

Analog for squares: A086009 (digit 1), and A086008 - A086017 for digits 0 - 9.

Sequence in context: A244600 A288558 A362831 * A086013 A340671 A167687

Adjacent sequences: A269238 A269239 A269240 * A269242 A269243 A269244

Keyword

nonn,base

Author

M. F. Hasler, Feb 20 2016

Status

approved