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.

A230099 a(n) = n + (product of digits of n).

Original entry on oeis.org

0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 20, 23, 26, 29, 32, 35, 38, 41, 44, 47, 30, 34, 38, 42, 46, 50, 54, 58, 62, 66, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 50, 56, 62, 68, 74, 80, 86, 92, 98, 104, 60, 67, 74, 81, 88, 95, 102, 109, 116, 123, 70, 78, 86, 94, 102, 110, 118, 126
Offset: 0

Views

Author

N. J. A. Sloane, Oct 12 2013

Keywords

Comments

A230099, A063114, A098736, A230101 are analogs of A092391 and A062028.

Links

Crossrefs

Cf. A007954, A011540, A092391, A062028, A004207, A230093, A003052, A176995.
Cf. also A063114, A098736, A230101, A230103, A230104, A230105, A062028, A230102, A063108.

Programs

  • Haskell
    a230099 n = a007954 n + n  -- Reinhard Zumkeller, Oct 13 2013
  • Maple
    with transforms; [seq(n+digprod(n), n=0..200)];
  • PARI
    a(n) = if (n, n + vecprod(digits(n)), 0); \\ Michel Marcus, Dec 18 2018
  • Python
    from math import prod
def a(n): return n + prod(map(int, str(n)))
print([a(n) for n in range(78)]) # Michael S. Branicky, Jan 09 2023

Formula

a(n) = n iff n contains a digit 0 (A011540). - Bernard Schott, Jul 31 2023

A098736 a(n) = product of n and all its digits.

Original entry on oeis.org

0, 1, 4, 9, 16, 25, 36, 49, 64, 81, 0, 11, 24, 39, 56, 75, 96, 119, 144, 171, 0, 42, 88, 138, 192, 250, 312, 378, 448, 522, 0, 93, 192, 297, 408, 525, 648, 777, 912, 1053, 0, 164, 336, 516, 704, 900, 1104, 1316, 1536, 1764, 0, 255, 520, 795, 1080, 1375, 1680, 1995
Offset: 0

Views

Author

Alexandre Wajnberg, Sep 30 2004

Keywords

Examples

			a(15) = 15*1*5=75

Links

Crossrefs

Cf. A007954, A230101.

Programs

  • Maple
    with transforms; [seq(n*digprod(n), n=0..200)]; # N. J. A. Sloane, Oct 12 2013
  • Mathematica
    Array[# Times@@ IntegerDigits@#&, 60, 0] (* Vincenzo Librandi, Oct 13 2013 *)
  • PARI
    a(n) = vecprod(digits(n))*n; \\ Michel Marcus, Aug 06 2020

Formula

If n=abcd (say) in decimal, then a(n) = abcd * a * b * c * d.
a(n) = n*A007954(n). - R. J. Mathar, Sep 27 2013

Extensions

More terms from Sam Alexander, Jan 06 2005
Corrected by Vincenzo Librandi, Oct 13 2013

A091788 a(1) = 1, a(2) = 2 and a(n) = product of the nonzero digits of all previous terms.

Original entry on oeis.org

1, 2, 2, 4, 16, 96, 5184, 829440, 1911029760, 13002646487040, 10065920762063093760, 9319918463639717615448883200, 137422208150223932126848386360776224407552000
Offset: 1

Views

Author

Amarnath Murthy, Feb 18 2004

Keywords

Links

Crossrefs

Cf. A051801, A230101.

Programs

  • Maple
    p:=proc(n) local pr,nn,j: pr:=1: nn:=convert(n,base,10): for j from 1 to nops(nn) do if nn[j]>0 then pr:=pr*nn[j] else pr:=pr: fi: od: end: a:=proc(n) if n=1 then 1 elif n=2 then 2 elif n=3 then 2 else a(n-1)*p(a(n-1)) fi end: seq(a(n),n=1..14); # p(n) is the product of the nonzero digits of n # Emeric Deutsch, Apr 15 2005

Formula

a(n) = a(n-1)*product of nonzero digits of a(n-1) (n >= 4). - Emeric Deutsch, Apr 15 2005

Extensions

More terms from Emeric Deutsch, Apr 15 2005
Showing 1-3 of 3 results.

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

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