A058422 -id:A058422 - cp's OEIS frontend

A058421 Numbers k such that k^2 contains only digits {0,1,8}, not ending with zero.

1, 9, 109, 901, 1009, 9001, 10009, 10401, 90001, 100009, 100901, 900001, 1000009, 1004001, 8954391, 9000001, 10000009, 10009001, 34351141, 90000001, 100000009, 100040001, 900000001, 1000000009, 1000090001, 3163554991, 9000000001, 10000000009, 10000400001

Offset: 1

Patrick De Geest, Nov 15 2000

Zhao Hui Du, Table of n, a(n) for n = 1..91
Patrick De Geest, Index to related sequences
Hisanori Mishima, Sporadic tridigital solutions

Cf. A058422.

Terms a(28) and above from Zhao Hui Du, Mar 07 2024

A119045 Triangular numbers composed of digits {0,1,8}.

Original entry on oeis.org

1, 10, 1081, 8001, 10011, 81810, 108811, 1188111, 8018010, 8801110, 10888111, 80118811, 88000011, 800180010, 881811010, 1088881111, 10808101800, 80001800010, 81108010180, 108888811111, 810008010801, 880818181011, 888000000111, 8000018000010, 10888888111111

Offset: 1

Giovanni Resta, May 10 2006

Giovanni Resta, Tridigital Triangular Numbers

Cf. A000217, A058422, A119046. See A119033 for a table of cross-references.

Rest[Select[FromDigits/@Tuples[{0,1,8},12],OddQ[Sqrt[8#+1]]&]] (* or *) Select[Accumulate[Range[1328*10^3]],SubsetQ[{0,1,8}, IntegerDigits[ #]]&](* Harvey P. Dale, May 06 2019 *)

a(n) = A000217(A119046(n)). - Michel Marcus, Mar 11 2023

a(23)-a(25) from Tyler Busby, Mar 11 2023

cp's OEIS Frontend

A058421 Numbers k such that k^2 contains only digits {0,1,8}, not ending with zero.

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