login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A272178 Absolute value of alternating row sum of row 2n in A238498. 0
1, 1, 2, 10, 54, 322, 1294, 4526, 20782, 93814, 371110, 1780294, 6733918, 22513642, 92018398, 461754862, 1297077342, 5790726826, 32850248974, 94597335398, 454725608974, 2080853077822, 6173935052878, 29922219241486, 116844904688830, 448338212337298, 1975870364475334 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
The alternating row sums of the odd-indexed rows are 0.
LINKS
Tom Edgar, Totienomial Coefficients, INTEGERS, 14 (2014), #A62.
FORMULA
For n>0, a(n) = Sum_{k=0..2n}(-1)^(k+1)*A238498(2n,k).
PROG
(Sage)
P=[0]+[i*prod([(1+1/x) for x in prime_divisors(i)]) for i in [1..100]]
Tr=[[prod(P[1:n+1])/(prod(P[1:k+1])*prod(P[1:(n-k)+1])) for k in [0..n]] for n in [0..len(P)-1]]
L=[sum((-1)^(i)*x[i] for i in [0..len(x)-1]) for x in Tr]
[abs(y) for y in L if y!=0]
CROSSREFS
Sequence in context: A102536 A221604 A163909 * A152395 A369263 A365879
KEYWORD
nonn
AUTHOR
Tom Edgar, Apr 21 2016
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 05:39 EDT 2024. Contains 371235 sequences. (Running on oeis4.)