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.

A132943 Concatenation of first n imperfect numbers.

Original entry on oeis.org

1, 12, 123, 1234, 12345, 123457, 1234578, 12345789, 1234578910, 123457891011, 12345789101112, 1234578910111213, 123457891011121314, 12345789101112131415, 1234578910111213141516, 123457891011121314151617
Offset: 1

Views

Author

Omar E. Pol, Oct 16 2007

Keywords

Links

Crossrefs

Imperfect numbers: A132999. Cf. A000396, A007908, A019518, A132928.

A134728 Concatenation of next n perfect numbers.

Original entry on oeis.org

6, 28496, 8128335503368589869056, 13743869132823058430081399521282658455991569831744654692615953842176191561942608236107294793378084303638130997321548169216
Offset: 1

Views

Author

Omar E. Pol, Nov 12 2007

Keywords

Comments

The next term -- a(5) -- has 1592 digits. - Harvey P. Dale, Apr 04 2022

Links

Crossrefs

Cf. A053067, A132928, A133013. Perfect numbers: A000396.

Programs

  • Mathematica
    Module[{nn=5},FromDigits[Flatten[IntegerDigits/@#]]&/@TakeList[ PerfectNumber[ Range[ (nn(nn+1))/2]],Range[nn]]] (* Harvey P. Dale, Apr 04 2022 *)
Showing 1-2 of 2 results.

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

Content is available under The OEIS End-User License Agreement.