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.

A239751 Numbers whose number of nonzero binary digits is less than their number of nonzero decimal digits.

Original entry on oeis.org

16, 32, 64, 128, 129, 132, 136, 144, 192, 256, 257, 258, 264, 272, 288, 384, 512, 513, 514, 516, 528, 544, 576, 768, 1024, 1025, 1026, 1028, 1032, 1056, 1088, 1152, 1153, 1154, 1156, 1168, 1184, 1216, 1280, 1281, 1282, 1284, 1288, 1296, 1312, 1344, 1536, 1537, 1538, 1544, 1552, 1568, 1664
Offset: 1

Views

Author

Michael Turniansky, Mar 26 2014

Keywords

Comments

If Hebrew gematria (A051596) were replaced with a "binary gematria" where aleph=1, bet=2, gimel=4, etc., this sequence would be a subset of "numbers whose binary gematria has fewer letters than their original gematria".

Crossrefs

Programs

  • APL
    ((+⌿(22⍴2)⊤C)<+⌿0≠(5⍴10)⊤C)/C←⍳10000
  • Mathematica
    Select[Range[1664], Less @@ Total /@ Sign /@ IntegerDigits[#, {2, 10}] &] (* Giovanni Resta, Mar 26 2014 *)

Formula

n such that A000120(n)<A055640(n).

A339073 Number of strings of Hebrew letters with a gematria value equal to n.

Original entry on oeis.org

1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1023, 2045, 4088, 8172, 16336, 32656, 65280, 130496, 260864, 521473, 1042434, 2083846, 4165649, 8327214, 16646264, 33276208, 66519792, 132974368, 265818368, 531376129, 1062231296, 2123421181, 4244760561, 8485359561, 16962400080, 33908170232, 67783096912
Offset: 1

Views

Author

Daniel Sterman, Nov 22 2020

Keywords

Comments

A051596-restricted compositions of n.

Examples

			The four strings with a gematria of 3 are:
אאא (111)
אב (12)
בא (21)
ג (3)
Note: Hebrew is written right-to-left, which is why the order of the digits appears to be reversed.
		

Crossrefs

Programs

  • Maple
    g:= 1/(1-add(x^i,i=1..9)-add(x^(10*i),i=1..9)-add(x^(100*i),i=1..4)):
    S:= series(g,x,101):
    seq(coeff(S,x,n),n=1..100); # Robert Israel, Nov 25 2020
  • Mathematica
    Table[SeriesCoefficient[1/(1 - Sum[x^j, {j, Join[Range[9], 10 Range[9], 100 Range[4]]}]), {x, 0, n}], {n, 100}] (* Jan Mangaldan, Nov 27 2020 *)

Formula

From Doron Zeilberger, Nov 23 2020: (Start)
G.f.: Sum(a(n)*x^n, n=0..infinity) =
1/(1-add(x^i,i=1..9)-add(x^(10*i),i=1..9)-add(x^(100*i),i=1..4))
= 1/(1-x-...-x^9 - x^10- ... -x^90 - x^100-x^200-x^300-x^400).
Asymptotics:
a(n) ~ 0.50221591060212746248115807725009875743325273964521...*(1.9990196005347377028156443471636402056440270173905...)^n
If alpha is the smallest positive root of P:=1-x-...-x^9 - x^10- ... -x^90 - x^100-x^200-x^300-x^400=0
then the above asymptotic formula is exactly -(alpha*P'(alpha))* (1/alpha)^n.
(End)

Extensions

More terms from Robert Israel, Nov 25 2020

A071061 Abjad values of the Arabic letters in the traditional order for abjad calculations.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000
Offset: 1

Views

Author

Koksal Karakus (karakusk(AT)hotmail.com), May 26 2002

Keywords

Comments

The Greek or Ionian numerals are similar, but omit 1000. - Charles R Greathouse IV, Jun 25 2012

Crossrefs

Subsequence of A037124.
Cf. A051596.
Showing 1-3 of 3 results.