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A119099
Triangular numbers composed of digits {1,2,4}.
2
1, 21, 2211, 222111, 1422141, 4244241, 22221111, 44241121, 124212441, 2222211111, 222222111111, 22222221111111, 1111114242224421, 2222222211111111, 21414424114444221, 222222222111111111, 1144211112222224221, 22222222221111111111, 44241214122411121441
OFFSET
1,2
FORMULA
a(n) = A000217(A119100(n)). - Michel Marcus, Mar 19 2023
CROSSREFS
Cf. A000217, A053881, A119100. See A119033 for a table of cross-references.
Sequence in context: A007593 A219104 A219983 * A319170 A359223 A215160
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, May 10 2006
EXTENSIONS
a(17)-a(19) from Tyler Busby, Mar 18 2023
STATUS
approved