A366961 Numbers whose difference between the largest and smallest digits is equal to 4.

15, 26, 37, 40, 48, 51, 59, 62, 73, 84, 95, 104, 115, 125, 135, 140, 145, 151, 152, 153, 154, 155, 204, 215, 226, 236, 240, 246, 251, 256, 262, 263, 264, 265, 266, 304, 315, 326, 337, 340, 347, 351, 357, 362, 367, 373, 374, 375, 376, 377, 400, 401, 402, 403, 404, 410

Offset

1,1

Comments

The number of n-digit terms is 29*5^(n-1) - 47*4^(n-1) + 2*3^(n+1).

Links

Table of n, a(n) for n=1..56.

Mathematica

Select[Range[410], Max[d=IntegerDigits[#]]-Min[d]==4 &]

Prog

(Python)
def ok(n): return max(d:=list(map(int, str(n))))-min(d) == 4
print([k for k in range(411) if ok(k)]) # Michael S. Branicky, Oct 30 2023
(PARI) isok(n) = my(d=digits(n)); vecmax(d) - vecmin(d) == 4; \\ Michel Marcus, Nov 05 2023

Crossrefs

Cf. A037904.

Cf. A010785 (difference = 0), A366958 (difference = 1), A366959 (difference = 2), A366960 (difference = 3), A366962 (difference = 5), A366963 (difference = 6), A366964 (difference = 7), A366965 (difference = 8), A366966 (difference = 9).

Sequence in context: A191915 A359547 A189045 * A032609 A050699 A097393

Adjacent sequences: A366958 A366959 A366960 * A366962 A366963 A366964

Keyword

nonn,base,easy

Author

Stefano Spezia, Oct 30 2023

Status

approved