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 1-3 of 3 results.

A379673 Records in A378865.

Original entry on oeis.org

2, 3, 4, 12, 22, 33, 38, 65, 112, 127, 222, 333, 625, 1112, 1247, 2222, 3333, 3612, 546875, 1640625, 48828125, 452734375, 4150390625, 225830078125, 11444091796875, 52674606084709, 155879785509415, 407757583839192, 342846312788889239, 434661425189366827, 483009317939766618
Offset: 1

Views

Author

Gonzalo Martínez, Jan 02 2025

Keywords

Crossrefs

Cf. A074157, A378865, A385290.

Extensions

a(19) onwards corrected by Jinyuan Wang and Sean A. Irvine, Jun 19 2025
More terms from Jinyuan Wang, Jun 25 2025

A385290 Indices of records in A378865.

Original entry on oeis.org

1, 12, 24, 49, 101, 102, 497, 498, 499, 501, 1001, 1002, 2864, 4999, 5001, 10001, 10002, 10624, 12864, 18624, 27648, 123648, 249856, 442368, 786432, 1259874, 2159784, 8249175, 8759124, 10236587, 10236758, 10237649, 10239674, 10239786, 10268473, 10427539, 10476523
Offset: 1

Views

Author

Jinyuan Wang, Jun 24 2025

Keywords

Crossrefs

Cf. A276348, A378865, A379673.

A074157 Smallest multiple of n which uses no digits of n, or 0 if no such number exists.

Original entry on oeis.org

2, 4, 6, 8, 10, 12, 14, 16, 18, 0, 22, 36, 26, 28, 30, 32, 34, 36, 38, 0, 63, 44, 46, 96, 100, 78, 54, 56, 58, 0, 62, 64, 66, 68, 70, 72, 111, 76, 78, 0, 82, 168, 86, 88, 90, 92, 188, 96, 588, 0, 204, 104, 106, 108, 110, 112, 114, 116, 118, 0, 244, 310, 189, 128
Offset: 1

Views

Author

Amarnath Murthy, Aug 29 2002

Keywords

Comments

For numbers n of the form 10k, of the form 10k+5 with a zero somewhere, and those using all 10 digits, a(n) = 0.
Are there numbers using 8 of the 9 nonzero digits for which a(n) is nonzero? If so, what is the smallest such number?
All such numbers have a(n) nonzero since a candidate value for a(n) is d*A052983(n) where d is the nonzero digit not in n. - Gonzalo Martínez, Dec 12 2024

Links

Crossrefs

Cf. A052983, A076924, A378865.

Programs

  • PARI
    a(n) = if(!(n%10), return(0)); my(dn = Set(digits(n))); if(#dn==10 || (#dn==9 && dn[1]==1), return(0)); if(!(n%5) && !dn[1], return(0)); if(!(n%2), my(v=setminus([0, 2, 4, 6, 8], dn)); if(!#v || (#v==1 && #dn==9 && valuation(n, 2)>valuation(v[1], 2)) || (v==[2, 6] && #dn==8 && valuation(n, 2)>1), return(0))); forstep(m=2*n, oo, n, if(!#setintersect(Set(digits(m)), dn), return(m))); \\ Michel Marcus, Aug 04 2017 (Corrected by Jinyuan Wang, Jun 15 2025)

Extensions

a(24) and a(49) corrected by Michel Marcus, Aug 04 2017
Showing 1-3 of 3 results.

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