A252079 Fixed points of permutations A252022 and A252023.

1, 2, 3, 4, 5, 36, 72, 125, 136, 900, 4454, 8021, 27223, 33905, 73222, 127536, 146353, 180177, 234668, 273241

Offset: 1

Author

Reinhard Zumkeller, Dec 13 2014

Keywords

• nonn
• more

Crossrefs

Cf. A252022, A252023, A252078.

Programs

Haskell

a252079 n = a252079_list !! (n-1)
a252079_list = [x | x <- [1..], a252022 x == x]

Python

A252079_list, l, s, b = [1], [1], 2, set()
for n in range(2, 10**5):
    i = s
    while True:
        if i not in b:
            li = [int(d) for d in str(i)[::-1]]
            for x, y in zip(li, l):
                if x+y > 9:
                    break
            else:
                l = li
                b.add(i)
                if i == n:
                    A252079_list.append(i)
                while s in b:
                    b.remove(s)
                    s += 1
                break
        i += 1 # Chai Wah Wu, Dec 14 2014

Extensions

a(16)-a(20) from Chai Wah Wu, Dec 14 2014