A039216 Numbers whose base-12 representation has the same number of 0's and 7's.

1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 32, 33, 34, 35, 37, 38, 39, 40, 41, 42, 44, 45, 46, 47, 49, 50, 51, 52, 53, 54, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 80, 81, 82, 83

Offset: 1

Author

Olivier Gérard

Keywords

• nonn
• base
• easy

Links

• David A. Corneth, Table of n, a(n) for n = 1..10000

Programs

PARI

f(n, b, d)=#select(x->x==d, digits(n, b));
for(n=1, 110, if (f(n, 12, 0)==f(n, 12, 7), print1(n, ", ")));\\ Petros Hadjicostas, Jul 08 2020

PARI

is(n) = {my(d = digits(n, 12), v = vector(12)); for(i = 1, #d, v[d[i]+1]++); v[1]==v[8]} \\ David A. Corneth, Jul 09 2020