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.

Previous Showing 11-16 of 16 results.

A133060 Concatenation of next n twin primes.

Original entry on oeis.org

3, 57, 111317, 19293141, 4359617173, 101103107109137139, 149151179181191193197, 199227229239241269271281, 283311313347349419421431433, 461463521523569571599601617619
Offset: 1

Views

Author

Omar E. Pol, Nov 10 2007

Keywords

Crossrefs

Programs

  • Mathematica
    Module[{pp=200,tps},tps=Union[Flatten[Select[Partition[Prime[Range[ pp]],2,1],#[[2]]-#[[1]]==2&]]];FromDigits[Flatten[ IntegerDigits/@#]]&/@ TakeList[tps,Range[Floor[(Sqrt[1+8Length[tps]]-1)/2]]]] (* Harvey P. Dale, Apr 06 2022 *)

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

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 *)

A134729 Concatenation of next n Sophie Germain primes A005384(n).

Original entry on oeis.org

2, 35, 112329, 41538389, 113131173179191, 233239251281293359, 419431443491509593641, 653659683719743761809911, 95310131019103110491103122312291289, 1409143914511481149915111559158316011733, 18111889190119311973200320392063206921292141
Offset: 1

Views

Author

Omar E. Pol, Nov 10 2007

Keywords

Crossrefs

Programs

  • Mathematica
    With[{sgp=Select[Prime[Range[500]],PrimeQ[2#+1]&]},Table[ FromDigits[ Flatten[IntegerDigits/@Take[sgp,{(n(n+1))/2+1,((n+1)(n+2))/2}]]],{n,0,11}]] (* Harvey P. Dale, Mar 24 2013 *)

Extensions

More terms from Harvey P. Dale, Mar 24 2013

A134793 Concatenation of next n nonprime numbers.

Original entry on oeis.org

1, 46, 8910, 12141516, 1820212224, 252627283032, 33343536383940, 4244454648495051, 525455565758606263, 64656668697072747576, 7778808182848586878890, 9192939495969899100102104105, 106108110111112114115116117118119120121
Offset: 1

Views

Author

Omar E. Pol, Nov 26 2007

Keywords

Crossrefs

Cf. A053067, A133013. Nonprime numbers: A018252.

Programs

  • Mathematica
    Module[{upto=35,comps,nn},nn=(upto(upto+1))/2;comps=Select[Range[nn], !PrimeQ[#]&];Table[FromDigits[Flatten[IntegerDigits/@Take[comps, {((i-1)(i))/2+1, (i(i+1))/2}]]],{i,25}]] (* Harvey P. Dale, Sep 10 2013 *)

Extensions

More terms from Harvey P. Dale, Sep 10 2013

A134796 Concatenation of next n positive oblong numbers.

Original entry on oeis.org

2, 612, 203042, 567290110, 132156182210240, 272306342380420462, 506552600650702756812, 87093099210561122119012601332, 140614821560164017221806189219802070
Offset: 1

Views

Author

Omar E. Pol, Nov 26 2007

Keywords

Comments

Oblong numbers are also called promic, pronic or heteromecic (numbers).

Crossrefs

Cf. A053067, A133013. Oblong numbers: A002378.

A134821 Concatenation of next n Motzkin numbers.

Original entry on oeis.org

1, 12, 4921, 51127323835, 218857981551141835113634, 310572853467235677965363821819928450852019, 1425475594007632231129760415319272779790434025012566981847673007772802
Offset: 1

Views

Author

Omar E. Pol, Nov 12 2007

Keywords

Crossrefs

Cf. A053067, A053068, A133013. Motzkin numbers: A001006.

Extensions

Edited by Charles R Greathouse IV, Apr 25 2010
Previous Showing 11-16 of 16 results.