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A119121
Triangular numbers composed of digits {1,3,9}.
2
1, 3, 91, 193131, 9939111, 119993391339919111, 199913191913191191, 399139119131339931, 139191313119199339131, 1313933311991311991139331, 3131199393919119319199931, 31313993393319311993391131311, 1191131333139133131313199933931
OFFSET
1,2
FORMULA
a(n) = A000217(A119122(n)).
CROSSREFS
Cf. A000217, A119122. See A119033 for a table of cross-references.
Sequence in context: A331672 A213978 A318129 * A213987 A297479 A116161
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, May 10 2006
EXTENSIONS
a(13) from Tyler Busby, Mar 28 2023
STATUS
approved