The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A345351 Triangular numbers such that the sum of cubes of their digits is prime. 0
 496, 946, 1378, 2485, 7381, 7750, 8128, 10011, 11935, 12880, 13366, 13861, 14365, 15931, 19900, 31375, 33670, 34453, 35245, 36046, 38503, 41905, 43660, 44551, 45451, 46360, 48205, 49141, 50086, 58996, 65341, 66430, 73153, 103285, 104653, 111628, 114481, 124750 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The cubes of the digits of 496 are 64, 729, and 216. They sum up to a prime number 1009. Thus, 496 is in the sequence. LINKS Table of n, a(n) for n=1..38. MATHEMATICA Select[Table[n (n + 1)/2, {n, 500}], PrimeQ[Total[IntegerDigits[#]^3]] &] PROG (Python) from sympy import isprime def A000217(n): return n*(n+1)//2 def A055012(n): return sum(int(d)**3 for d in str(n)) def ok(tri): return isprime(A055012(tri)) print(list(filter(ok, (A000217(n) for n in range(500))))) # Michael S. Branicky, Jun 15 2021 CROSSREFS Cf. A000217. Sequence in context: A214555 A333756 A179170 * A157447 A109477 A302366 Adjacent sequences: A345348 A345349 A345350 * A345352 A345353 A345354 KEYWORD nonn,base,less AUTHOR Tanya Khovanova, Jun 15 2021 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.

Last modified September 16 05:57 EDT 2024. Contains 375959 sequences. (Running on oeis4.)