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.

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A119162 Triangular numbers composed of digits {2,4,8}.

Original entry on oeis.org

28, 48828, 828828, 842288428828, 24884484228828, 28284882828828, 2842448222228428828
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Comments

a(8) > 10^40. - Tyler Busby, Mar 29 2023

Links

Crossrefs

Cf. A000217, A027678, A119163. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119163(n)). - Tyler Busby, Mar 29 2023

A119164 Triangular numbers composed of digits {2,5,6}.

Original entry on oeis.org

6, 55, 66, 666, 2556, 5565, 6555, 26565, 255255, 2265256, 5656566, 55656525, 525252666, 2665266555, 2666226566655, 6655522556665, 56625555222225, 265556626652565, 555665666566566, 2626662552255225, 6225222656552266, 26256252552656556, 652265255255252222566
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Links

Crossrefs

Cf. A000217, A030484, A119165. See A119033 for a table of cross-references.

Programs

  • Mathematica
    Flatten[Table[Select[FromDigits/@Tuples[{2,5,6},n],OddQ[Sqrt[8#+1]]&],{n,16}]] (* Harvey P. Dale, Nov 03 2015 *)

Formula

a(n) = A000217(A119165(n)).

Extensions

a(22)-a(23) from Tyler Busby, Mar 24 2023

A119166 Triangular numbers composed of digits {2,5,7}.

Original entry on oeis.org

55, 2775, 255255, 577275, 572755525755, 2577527227575, 727275225222727525, 2257227755272522252275, 52722757572552577725225, 272527775757277272275522727772752527575
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Comments

a(11) > 10^40. - Tyler Busby, Mar 28 2023

Links

Crossrefs

Cf. A000217, A030485, A119167. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119167(n)). - Tyler Busby, Mar 28 2023

Extensions

a(10) from Tyler Busby, Mar 28 2023

A119168 Triangular numbers composed of digits {2,5,8}.

Original entry on oeis.org

28, 55, 528, 255255, 525825, 828828, 22528828, 58855825, 88252255, 285258555, 252852582885, 255285258288528, 255828252825225, 825882525828828, 255888285855228855, 555888585855288828885, 55255285258252252552225, 282882828558888582552522225, 528225588525528822525588858528585
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Links

Crossrefs

Cf. A000217, A053927, A119169. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119169(n)). - Tyler Busby, Mar 28 2023

Extensions

a(18)-a(19) from Tyler Busby, Mar 28 2023

A119170 Triangular numbers composed of digits {2,5,9}.

Original entry on oeis.org

55, 595, 5995, 255255, 292995, 299925, 25952229225, 99292929555225, 55955525255559595, 555959229929999252295, 925952955522559552259925, 5299552922255552929595999295, 5995959559225555222929295255522595295, 9925559955529295222599225259529552225
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Comments

a(15) > 10^40. - Tyler Busby, Mar 24 2023

Links

Crossrefs

Cf. A000217, A053929, A119171. See A119033 for a table of cross-references.

Programs

  • Mathematica
    Flatten[Table[Select[FromDigits /@ Tuples[{2, 5, 9}, n], IntegerQ[(Sqrt[8 # + 1] - 1)/2] &], {n, 11}]] (* Amiram Eldar, Nov 30 2018 *)

Formula

a(n) = A000217(A119171(n)).
a(n) == 5 (mod 10) for all n. - Chai Wah Wu, Nov 30 2018

Extensions

a(13)-a(14) from Tyler Busby, Mar 24 2023

A119172 Triangular numbers composed of digits {2,6,7}.

Original entry on oeis.org

6, 66, 276, 666, 7626, 6666726, 77666666626, 2662627722726, 2777672627676766, 77772662277672726, 6622726277766676626, 672667762262676277666726
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Comments

a(13) > 10^40. - Tyler Busby, Mar 29 2023

Links

Crossrefs

Cf. A000217, A058462, A119173. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119173(n)). - Tyler Busby, Mar 29 2023

A119174 Triangular numbers composed of digits {2,6,8}.

Original entry on oeis.org

6, 28, 66, 666, 2628, 228826, 828828, 2222886, 66268828, 222868828, 286262628, 628262628, 688668828, 862266628, 2266226826, 622686668286628, 866688628826628, 68262228626828682628, 288626826822666288666, 66288228282628868868828, 28622882886686262262866288686266
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Links

Crossrefs

Cf. A000217, A119175. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119175(n)). - Tyler Busby, Mar 28 2023

Extensions

a(20)-a(21) from Tyler Busby, Mar 28 2023

A119176 Triangular numbers composed of digits {2,6,9}.

Original entry on oeis.org

6, 66, 666, 2926, 29962999696266, 226966926929226, 9996922966699222296, 296292269222296622226, 22266696966226666966622226, 266669269626696962299266226222926
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Comments

a(11) > 10^40. - Tyler Busby, Mar 28 2023

Links

Crossrefs

Cf. A000217, A053931, A119177. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119177(n)). - Tyler Busby, Mar 28 2023

Extensions

a(10) from Tyler Busby, Mar 28 2023

A119178 Triangular numbers composed of digits {2,7,8}.

Original entry on oeis.org

28, 78, 2278, 8778, 222778, 828828, 887778, 8272278, 22227778, 88278828, 88877778, 2222277778, 2882872278, 8882778828, 8888777778, 222222777778, 888827778828, 888887777778, 22222227777778, 88888277778828, 88888877777778, 228887828777278, 272277272227278
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Links

Crossrefs

Cf. A000217, A119179. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119179(n)). - Michel Marcus, Mar 22 2023

Extensions

a(21)-a(23) from Tyler Busby, Mar 22 2023

A119180 Triangular numbers composed of digits {2,8,9}.

Original entry on oeis.org

28, 828828, 9298828, 99228828, 2882992822228828, 88992922889298828, 299282229288828999298828
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Comments

a(8) > 10^40. - Tyler Busby, Mar 29 2023

Links

Crossrefs

Cf. A000217, A053935, A119181. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119181(n)). - Tyler Busby, Mar 29 2023
Previous Showing 71-80 of 112 results. Next

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

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