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: Yohei Furutono

Yohei Furutono's wiki page.

Yohei Furutono has authored 3 sequences.

A298729 Prime numbers whose decimal expansion includes a substring of seven consecutive 7's.

Original entry on oeis.org

137777777, 177777773, 177777779, 197777777, 307777777, 347777777, 437777777, 527777777, 547777777, 577777777, 587777777, 647777777, 697777777, 777777701, 777777739, 777777743, 777777751, 777777799, 787777777, 827777777, 947777777, 967777777, 1247777777, 1277777771, 1277777773, 1457777777, 1487777777
Offset: 1

Author

Yohei Furutono, Jan 25 2018

Keywords

Crossrefs

Programs

  • Mathematica
    s = {7, 7, 7, 7, 7, 7, 7}; lst = {}; k = 1; While[k < 10001, l = 1; il = 12;
    While[l < il, p = FromDigits@ Flatten@ Insert[ IntegerDigits[k, 10, 10], s, l];
      If[PrimeQ@ p, AppendTo[lst, p]]; l++]; k++]; Union@ lst (* Robert G. Wilson v, Feb 08 2018 *)
  • PARI
    is(n) = my(v=vector(7, x, 7), d=digits(n)); for(k=1, #d-6, if([d[k], d[k+1], d[k+2], d[k+3], d[k+4], d[k+5], d[k+6]]==v, return(1))); 0
    forprime(p=1, , if(is(p), print1(p, ", "))) \\ Felix Fröhlich, Mar 06 2018

A298720 EBCDIC codes for lower case letters.

Original entry on oeis.org

129, 130, 131, 132, 133, 134, 135, 136, 137, 145, 146, 147, 148, 149, 150, 151, 152, 153, 162, 163, 164, 165, 166, 167, 168, 169
Offset: 1

Author

Yohei Furutono, Jan 25 2018

Comments

Extended Binary Coded Decimal Interchange Code.

Examples

			Corresponding hexadecimal values: 81, 82, 83, 84, 85, 86, 87, 88, 89, 91, 92, 93, 94, 95, 96, 97, 98, 99, A2, A3, A4, A5, A6, A7, A8, A9.
For example, 'a' is 81, 'b' is 82, ..., 'z' is A9.
		

Crossrefs

Programs

  • Mathematica
    With[{r = Range@ 9}, Flatten@ {2^7 + {r, 2^4 + r, 2^5 + Rest[r]}}] (* Michael De Vlieger, Jan 28 2018 *)

A298728 EBCDIC codes for upper case letters.

Original entry on oeis.org

193, 194, 195, 196, 197, 198, 199, 200, 201, 209, 210, 211, 212, 213, 214, 215, 216, 217, 226, 227, 228, 229, 230, 231, 232, 233
Offset: 1

Author

Yohei Furutono, Jan 25 2018

Comments

Extended Binary Coded Decimal Interchange Code.

Examples

			Hexadecimal values: C1, C2, C3, C4, C5, C6, C7, C8, C9, D1, D2, D3, D4, D5, D6, D7, D8, D9, E2, E3, E4, E5, E6, E7, E8, E9.
For example, 'A' is C1, 'B' is C2, ..., 'Z' is E9.
		

Crossrefs

Programs

  • Mathematica
    With[{r = Range@ 9}, Flatten@ {2^7 + 2^6 + {r, 2^4 + r, 2^5 + Rest[r]}}] (* Michael De Vlieger, Jan 28 2018 *)