cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

User: Jason Wang

Jason Wang's wiki page.

Jason Wang has authored 2 sequences.

A340177 Decimal expansion of Sum_{i>=1} sin(1/i)^i.

Original entry on oeis.org

1, 1, 1, 0, 4, 2, 6, 2, 0, 3, 3, 5, 8, 6, 4, 8, 8, 0, 1, 9, 4, 9, 9, 2, 6, 9, 7, 5, 7, 8, 4, 0, 8, 0, 9, 2, 0, 1, 6, 2, 3, 7, 4, 7, 3, 9, 9, 1, 1, 7, 2, 2, 0, 4, 9, 0, 6, 5, 8, 9, 1, 7, 8, 1, 8, 5, 6, 0, 4, 8, 4, 5, 1, 9, 5, 4, 7, 1, 8, 0, 4, 7, 6, 3, 9, 7, 2
Offset: 1

Author

Jason Wang, Dec 30 2020

Keywords

Examples

			1.1104262033586488019499269757840809201623747399117220...
		

Programs

  • Maple
    evalf[132](sum(sin(1/i)^i, i = 1 .. infinity));
  • PARI
    suminf(i=1,sin(1/i)^i) \\ Hugo Pfoertner, Dec 30 2020

A285056 a(n) = the first positive integer, not ending in zero, whose cube has a substring of exactly n identical digits.

Original entry on oeis.org

1, 11, 126, 753, 1923, 32183, 134708, 1487139, 23908603, 215443469, 106917811, 15056809703, 27354803113, 681048619195, 361160395301
Offset: 1

Author

Jason Wang, Apr 08 2017

Keywords

Examples

			a(3) = 126, as 126^3 = 2000376 contains a digit (0) repeated n (3) times.
		

Crossrefs

Cf. A167712.

Programs

  • Mathematica
    a[n_] := Block[{k=1}, While[Mod[k, 10] == 0 || ! MemberQ[Length /@ Split[ IntegerDigits[ k^3]], n], k++]; k]; Array[a, 8] (* Giovanni Resta, Apr 10 2017 *)
  • Python
    import collections
    import re
    cur = 1
    def repeat( num , reps ):
        r = str(num)
        n = 1
        while n < reps:
            r += str(num)
            n += 1
        return r;
    while True:
        k = 0
        while k < 10:
            rep = repeat(k,9)
            while re.search(rep, str(cur**3)) != None:
                if re.search(rep + str(k), str(cur**3)) == None:
                    print(str(cur) + ", " + str(cur**3))
                    rep += str(k)
                else:
                    rep += str(k)
            k += 1
        cur += 1
        if cur % 10 == 0:
            cur += 1 #note: this will display all cubes with a substring of 9 repeated digits. To change this to n repeats, replace repeat(k,9) with repeat(k,n).

Extensions

a(10)-a(15) from Giovanni Resta, Apr 10 2017