The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A119135 Numbers k such that the k-th triangular number contains only digits {1,5,7}. 2
1, 5, 10, 18, 58, 101, 149, 1050, 1885, 5925, 10114, 15173, 47226, 550594, 585005, 1049925, 1533085, 56174285, 104987349, 123053789, 1017425330, 1230586669, 1245114914, 38878044589, 101111538130, 177627538130, 4728038741701 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
MATHEMATICA
Select[Range[2 10^7], Complement[IntegerDigits[Binomial[# + 1, 2]], {1, 5, 7}] == {}&] (* Vincenzo Librandi, Oct 07 2015 *)
PROG
(Magma) [n: n in [1..2*10^7] | Set(Intseq(Binomial(n+1, 2))) subset [1, 5, 7]]; // Vincenzo Librandi, Oct 07 2015
CROSSREFS
Cf. A000217, A119134. See A119034 for a table of cross-references.
Sequence in context: A296552 A251928 A153370 * A083287 A091922 A030776
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, May 10 2006
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 13 22:21 EDT 2024. Contains 373391 sequences. (Running on oeis4.)