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A366057
Expansion of (1/x) * Series_Reversion( x/(1-x+x^5) ).
1
1, -1, 1, -1, 1, 0, -5, 20, -55, 125, -246, 406, -461, -144, 3004, -11978, 35113, -86293, 181663, -314603, 365922, 150023, -2696308, 10969573, -32970453, 82976409, -178372934, 314133884, -367436684, -179661091, 2923282216, -11972239216, 36369188841, -92517132841
OFFSET
0,7
FORMULA
a(n) = (1/(n+1)) * Sum_{k=0..floor(n/5)} (-1)^(n-k) * binomial(n+1,k) * binomial(n-k+1,n-5*k).
PROG
(PARI) a(n) = sum(k=0, n\5, (-1)^(n-k)*binomial(n+1, k)*binomial(n-k+1, n-5*k))/(n+1);
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Sep 27 2023
STATUS
approved