A273046
Fibonacci numbers with digits in nonincreasing order.
Original entry on oeis.org
0, 1, 1, 2, 3, 5, 8, 21, 55, 610, 987
Offset: 1
-
Select[Fibonacci@ Range[0, 10^4], Reverse@ Sort@ # == # &@ IntegerDigits@ # &] (* Michael De Vlieger, May 13 2016 *)
-
fibmod(n,m)=lift(((Mod([1,1;1,0],m))^n)[1,2])
isA009996(n)=my(d=digits(n)); vecsort(d,,4)==d
B1=10^9;B2=10^57;
for(n=1,1e9, if(isA009996(fibmod(n,B1)) && isA009996(fibmod(n,B2)) && isA009996(F=fibonacci(n)), print1(F", "))) \\ Charles R Greathouse IV, May 17 2016
A352721
Perfect cubes whose decimal digits appear in nonincreasing order.
Original entry on oeis.org
0, 1, 8, 64, 1000, 8000, 64000, 1000000, 8000000, 64000000, 1000000000, 8000000000, 64000000000, 1000000000000, 8000000000000, 64000000000000, 1000000000000000, 8000000000000000, 64000000000000000, 1000000000000000000, 8000000000000000000, 64000000000000000000
Offset: 1
64 is in the sequence because it is a perfect cube (64 = 4^3) whose digits appear in nonincreasing order.
-
Select[Range[0, 4*10^6]^3, Max@ Differences[IntegerDigits[#]] <= 0 &] (* Amiram Eldar, Mar 30 2022 *)
-
ok(n) = digits(n) == vecsort(digits(n),,4) && ispower(n,3)
Showing 1-2 of 2 results.
Comments