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A366960 Numbers whose difference between the largest and smallest digits is equal to 3.

%I A366960 #24 Apr 04 2024 12:35:52
%S A366960 14,25,30,36,41,47,52,58,63,69,74,85,96,103,114,124,130,134,141,142,
%T A366960 143,144,203,214,225,230,235,241,245,252,253,254,255,300,301,302,303,
%U A366960 310,314,320,325,330,336,341,346,352,356,363,364,365,366,411,412,413,414
%N A366960 Numbers whose difference between the largest and smallest digits is equal to 3.
%C A366960 The number of n-digit terms of this sequence is 27*4^(n-1) - 41*3^(n-1) + 7*2^n.
%H A366960 Stefano Spezia, <a href="/A366960/b366960.txt">Table of n, a(n) for n = 1..10000</a>
%t A366960 Select[Range[415],Max[d=IntegerDigits[#]]-Min[d]==3 &]
%o A366960 (Python)
%o A366960 def ok(n): return max(d:=list(map(int, str(n))))-min(d) == 3
%o A366960 print([k for k in range(420) if ok(k)]) # _Michael S. Branicky_, Oct 30 2023
%o A366960 (Python)
%o A366960 from itertools import chain, count, islice, combinations_with_replacement
%o A366960 from sympy.utilities.iterables import multiset_permutations
%o A366960 def A366960_gen(): # generator of terms
%o A366960     return chain.from_iterable(sorted(int(''.join(str(d) for d in t)) for a in range(7) for c in combinations_with_replacement(range(a,a+4),l) for t in multiset_permutations((a,a+3)+c) if t[0]) for l in count(0))
%o A366960 A366960_list = list(islice(A366960_gen(),30)) # _Chai Wah Wu_, Nov 10 2023
%o A366960 (PARI) isok(n) = my(d=digits(n)); vecmax(d) - vecmin(d) == 3; \\ _Michel Marcus_, Nov 05 2023
%Y A366960 Cf. A037904.
%Y A366960 Cf. A010785 (difference = 0), A366958 (difference = 1), A366959 (difference = 2), A366961 (difference = 4), A366962 (difference = 5), A366963 (difference = 6), A366964 (difference = 7), A366965 (difference = 8), A366966 (difference = 9).
%K A366960 nonn,base,easy
%O A366960 1,1
%A A366960 _Stefano Spezia_, Oct 30 2023