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.

A104419 Numbers n such that n, p[n], p[n]+n, p[n]-n and p[n]*n all are 0-less.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 8, 12, 13, 16, 19, 21, 24, 25, 31, 32, 35, 36, 43, 44, 45, 46, 47, 49, 51, 52, 53, 57, 58, 59, 61, 62, 67, 69, 72, 77, 83, 84, 85, 91, 94, 99, 115, 116, 118, 125, 129, 133, 142, 146, 162, 166, 167, 168, 188, 192, 194, 195, 196
Offset: 1

Views

Author

Zak Seidov, Mar 07 2005

Keywords

Examples

			n=8 is OK because 8, p[8]=19, 19+8=27, 19-8=11, 19*8=152 all are 0-less; n=7 is not because p[7]-7=17-7=10 is not 0-less.
		

Programs

  • Mathematica
    id[x_]:=IntegerDigits[x];pr[i_]:=Prime[i];ra=Range[200];A104419=Select[ra, Union[id[ # ], id[pr[ # ]], id[pr[ # ]+# ], id[pr[ # ]-# ], id[pr[ # ]*# ]][[1]]!=0&]