The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A155105 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A155105

Positive numbers appearing in the third column of A155103.
(history; published version)

#33 by N. J. A. Sloane at Fri Oct 25 09:54:29 EDT 2024

STATUS

proposed

approved

#32 by Hugo Pfoertner at Thu Oct 03 03:30:23 EDT 2024

STATUS

editing

proposed

#31 by Hugo Pfoertner at Thu Oct 03 03:28:56 EDT 2024

PROG

(PARI) \\ after R. J. Mathar

T(n, k)=if(n==k, 1, if(n==2*k, -(k+1))); \\ from A155102

\\ First term = 1 omitted

a155103(upto) = my(m=3*2^upto, a=matid(m)); for(r=1, m, forstep(c=r-1, 1, -1, a[r, c]=-sum(cp=c, r-1, a[cp, c]*T(r, cp)); if(c==3 && a[r, c]!=0, print1(a[r, c], ", "))));

a155103(8) \\ Hugo Pfoertner, Oct 03 2024

STATUS

proposed

editing

#30 by Hugo Pfoertner at Thu Oct 03 00:53:51 EDT 2024

STATUS

editing

proposed

Discussion

Thu Oct 03

01:05

Michel Marcus: please add PARI program

#29 by Hugo Pfoertner at Thu Oct 03 00:49:39 EDT 2024

DATA

1, 4, 28, 364, 9100, 445900, 43252300, 8347693900, 3213862151500, 2471459994503500, 3798634011551879500, 11673202317498925703500

COMMENTS

More terms added with the recurrence relation. - Tristan Cam, Oct 02 2024

PROG

(Python)

def seq(k):

s = [1]

for i in range(k-1):

s.append(s[-1]*(1+3*(1<<i)))

return s

# Tristan Cam, Oct 02 2024

EXTENSIONS

a(8)-a(1112) from Hugo Pfoertner, Oct 02 2024

STATUS

proposed

editing

Discussion

Thu Oct 03

00:53

Hugo Pfoertner: As mentioned by other editors, we need a proof before we can use the conjectured formulas in a program and in an extension of the sequence.

#28 by Hugo Pfoertner at Wed Oct 02 16:36:06 EDT 2024

STATUS

editing

proposed

#27 by Hugo Pfoertner at Wed Oct 02 16:33:16 EDT 2024

DATA

1, 4, 28, 364, 9100, 445900, 43252300, 8347693900, 3213862151500, 2471459994503500, 3798634011551879500, 11673202317498925703500, 71731828241030898448007500, 881512437254028711027564167500, 21664931170392263630924444544647500

EXTENSIONS

a(8)-a(11) from Hugo Pfoertner, Oct 02 2024

STATUS

proposed

editing

Discussion

Wed Oct 02

16:36

Hugo Pfoertner: Found one more term, using the PARI translation of Richard's program. Removed the -although highly likely correct- conjectured terms.

#26 by Robert C. Lyons at Wed Oct 02 12:00:44 EDT 2024

STATUS

editing

proposed

Discussion

Wed Oct 02

12:33

Michel Marcus: More terms added with the recurrence relation : normally this would have to be entered in Extension section

12:33

Michel Marcus: BUT normally you cannot add terms based on a conjecture

12:38

Tristan Cam: My bad, feel free to remove.

15:57

Hugo Pfoertner: I can confirm the terms up to 2471459994503500 using a dumb PARI transcription of Richard Mathar's Maple program.

#25 by Robert C. Lyons at Wed Oct 02 12:00:28 EDT 2024

PROG

_# _Tristan Cam_, Oct 02 2024

STATUS

proposed

editing

#24 by Tristan Cam at Wed Oct 02 11:47:40 EDT 2024

STATUS

editing

proposed