A095090 - OEIS

A095090

Number of 4k+3 integers in range ]2^n,2^(n+1)] whose Jacobi-vector is a Motzkin-path (A095100).

1, 1, 2, 3, 6, 9, 17, 33, 60, 108, 202, 360, 703, 1328, 2519, 4779, 9103, 17501, 33473, 64761

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OFFSET

1,3

LINKS

FORMULA

a(n) = 2^(n-2) - A095091(n) for n > 1.

PROG

(PARI) is(m) = {my(s=0); for(i=1, m-1, if((s+=kronecker(i, m))<0, return(0))); 1; }

a(n) = {my(c=0); forstep(m=2^n+3-(n==1), 2^(n+1), 4, c+=is(m)); c; } \\ Jinyuan Wang, Jul 20 2020

CROSSREFS

KEYWORD

nonn,more

AUTHOR

Antti Karttunen and Jun 01 2004

STATUS

approved