A046831 Numbers k such that decimal expansion of k^2 contains k as a substring and k does not end in 0.

1, 5, 6, 25, 76, 376, 625, 3792, 9376, 14651, 90625, 109376, 495475, 505025, 890625, 971582, 1713526, 2890625, 4115964, 5133355, 6933808, 7109376, 10050125, 12890625, 48588526, 50050025, 66952741, 87109376, 88027284, 88819024

Offset

1,2

Comments

Subsequence of A018834. - Chai Wah Wu, Apr 04 2023

Links

Giovanni Resta, Table of n, a(n) for n = 1..64

Mathematica

Reap[For[n = 1, n < 10^8, n++, If[Mod[n, 10] != 0, If[StringPosition[ToString[n^2], ToString[n]] != {}, Print[n]; Sow[n]]]]][[2, 1]] (* Jean-François Alcover, Apr 04 2013 *)

Prog

(Haskell)
a046831 n = a046831_list !! (n-1)
a046831_list = filter ((> 0) . (`mod` 10)) a018834_list
-- Reinhard Zumkeller, Jul 27 2011
(Python)
from itertools import count, islice
def A046831_gen(startvalue=0): # generator of terms >= startvalue
    return filter(lambda n:n%10 and str(n) in str(n**2), count(max(startvalue, 0)))
A046831_list = list(islice(A046831_gen(), 20)) # Chai Wah Wu, Apr 04 2023

Crossrefs

Cf. A018834, A003226, A008851.

Sequence in context: A034497 A136888 A038248 * A003226 A088834 A137081

Adjacent sequences: A046828 A046829 A046830 * A046832 A046833 A046834

Keyword

nonn,base

Author

David W. Wilson

Status

approved