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Revision History for A117401 (Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

Showing entries 1-10 | older changes
Triangle T(n,k) = 2^(k*(n-k)), read by rows.
(history; published version)
#36 by Jon E. Schoenfield at Mon Feb 07 00:29:30 EST 2022
STATUS

editing

approved

#35 by Jon E. Schoenfield at Mon Feb 07 00:29:25 EST 2022
FORMULA

Equals ConvOffsStoT transform of the 2^n series: (1, 2, 4, 8, ...); e.g., ConvOffs transform of (1, 2, 4, 8) = (1, 8, 16, 8, 1). - Gary W. Adamson, Apr 21 2008

PROG

(MAGMAMagma)

STATUS

approved

editing

#34 by Joerg Arndt at Tue Jun 29 02:30:59 EDT 2021
STATUS

reviewed

approved

#33 by Michel Marcus at Mon Jun 28 22:43:49 EDT 2021
STATUS

proposed

reviewed

#32 by G. C. Greubel at Mon Jun 28 21:30:50 EDT 2021
STATUS

editing

proposed

#31 by G. C. Greubel at Mon Jun 28 21:30:21 EDT 2021
NAME

Triangle, T(n,k) = 2^(k*(n-k)), read by rows, defined by: T(n,k) = 2^((n-k)*k) for n>=k>=0.

DATA

1, 1, 1, 1, 2, 1, 1, 4, 4, 1, 1, 8, 16, 8, 1, 1, 16, 64, 64, 16, 1, 1, 32, 256, 512, 256, 32, 1, 1, 64, 1024, 4096, 4096, 1024, 64, 1, 1, 128, 4096, 32768, 65536, 32768, 4096, 128, 1, 1, 256, 16384, 262144, 1048576, 1048576, 262144, 16384, 256, 1, 1, 512, 65536

LINKS

G. C. Greubel, <a href="/A117401/b117401.txt">Rows n = 0..50 of the triangle, flattened</a>

FORMULA

T(n,k) = (1/n)*[( 2^(n-k)*k*T(n-1,k-1) + 2^k*(n-k)*T(n-1,k)], ), where T(i,j)=0 if j>i. - Tom Edgar, Feb 20 2014

T(n, k, m) = (m+2)^(k*(n-k)) with m = 0. - G. C. Greubel, Jun 28 2021

EXAMPLE

1;

1, 1;

1, 2, 1;

1, 4, 4, 1;

1, 8, 16, 8, 1;

1, 16, 64, 64, 16, 1;

1, 32, 256, 512, 256, 32, 1;

1, 64, 1024, 4096, 4096, 1024, 64, 1;

1, 128, 4096, 32768, 65536, 32768, 4096, 128, 1;

1, 256, 16384, 262144, 1048576, 1048576, 262144, 16384, 256, 1; ...

PROG

(MAGMA)

A117401:= func< n, k, m | (m+2)^(k*(n-k)) >;

[A117401(n, k, 0): k in [0..n], n in [0..12]]; // G. C. Greubel, Jun 28 2021

(Sage)

def A117401(n, k, m): return (m+2)^(k*(n-k))

flatten([[A117401(n, k, 0) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Jun 28 2021

CROSSREFS

Cf. this sequence (m=0), A118180 (m=1), A118185 (m=2), A118190 (m=3), A158116 (m=4), A176642 (m=6), A158117 (m=8), A176627 (m=10), A176639 (m=13), A156581 (m=15).

STATUS

approved

editing

#30 by Joerg Arndt at Tue Jun 02 01:56:19 EDT 2020
STATUS

reviewed

approved

#29 by Peter Luschny at Tue Jun 02 01:52:57 EDT 2020
STATUS

proposed

reviewed

#28 by Joerg Arndt at Mon Jun 01 02:10:55 EDT 2020
STATUS

editing

proposed

#27 by Joerg Arndt at Mon Jun 01 02:10:51 EDT 2020
FORMULA

Let E(x) = Sum_{n>=0 } x^n/2^C(n,2). Then E(x)*E(y*x) = Sum_{n>=0 } Sum_{k=0..n} T(n,k)*y^k*x^n/2^C(n,2). - Geoffrey Critzer, May 31 2020

STATUS

proposed

editing