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.

Showing 1-2 of 2 results.

A110070 Numbers n such that n=pi(d_1!*d_2!*...*d_k!) where d_1 d_2 ... d_k is the decimal expansion of n.

Original entry on oeis.org

0, 3, 34, 52, 2800414
Offset: 1

Views

Author

Farideh Firoozbakht, Jul 22 2005

Keywords

Comments

No other terms below 10^15. - Max Alekseyev, Jul 21 2024

Examples

			2800414 is in the sequence because 2800414=pi(2!*8!*0!*0!*4!*1!*4!).

Crossrefs

Cf. A110071, A110072, A097220, A097223, A097227, A098683, A098684, A098685.

A110071 Numbers n such that n = pi(d_1!!*d_2!!*...*d_k!!) where d_1 d_2 ... d_k is the decimal expansion of n.

Original entry on oeis.org

0, 4, 290, 11387, 1656281, 538311474096
Offset: 1

Views

Author

Farideh Firoozbakht, Jul 22 2005

Keywords

Comments

No other terms below 10^14. - Max Alekseyev, Jul 21 2024

Examples

			11387 is in the sequence because 11387 = pi(1!!*1!!*3!!*8!!*7!!).

Crossrefs

Cf. A000720, A006882, A097655, A110070, A110072.

Programs

  • Mathematica
    Do[h = IntegerDigits[n]; l = Length[h]; If[n == PrimePi[ Product[h[[k]]!!, {k, l}]], Print[n]], {n, 0, 50000}]

Extensions

a(5) added by Farideh Firoozbakht, Dec 02 2007
a(6) from Max Alekseyev, Jul 21 2024
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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