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 A274739 E.g.f.: A(x) = exp( Integral A(x)^x dx ). 2
 1, 1, 1, 3, 9, 41, 201, 1251, 8433, 66929, 572081, 5531491, 57181881, 652539993, 7907542969, 104062458371, 1445741857121, 21558272089441, 337695484081633, 5627841331360579, 98111012260861161, 1807282176961893641, 34700307936576464681, 700154636364071210403, 14679540320819927222609, 321986110832829347765201, 7319090450233578659328401, 173404394127560945064454051, 4247591743241187138230540953, 108102161282212302995364874809 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Compare the e.g.f. to the identities: (1) G(x) = exp( Integral G(x)^t dx ) when G(x) = 1/(1-t*x)^(1/t). (2) G(x) = 1 + Integral G(x)^(1+t) dx when G(x) = 1/(1-t*x)^(1/t). All terms appear to be odd. LINKS Paul D. Hanna, Table of n, a(n) for n = 0..300 FORMULA E.g.f.: A(x) = 1 + Integral A(x)^(1+x) dx. E.g.f.: A(x) = 1/A(-x). EXAMPLE E.g.f.: A(x) = 1 + x + x^2/2! + 3*x^3/3! + 9*x^4/4! + 41*x^5/5! + 201*x^6/6! + 1251*x^7/7! + 8433*x^8/8! + 66929*x^9/9! + 572081*x^10/10! + 5531491*x^11/11! + 57181881*x^12/12! +... where A(x) = exp( Integral A(x)^x dx ), also, A(x) = 1 + Integral A(x)^(1+x) dx. RELATED SERIES. The e.g.f. satisfies: A(x)' = A(x)^(1+x), which begins: A(x)^(1+x) = 1 + x + 3*x^2/2! + 9*x^3/3! + 41*x^4/4! + 201*x^5/5! + 1251*x^6/6! + 8433*x^7/7! +  + 66929*x^8/8! + 572081*x^9/9! + 5531491*x^10/10! +... The series A(x)^x = A(x)'/A(x) is an even function that begins: A(x)^x = 1 + 2*x^2/2! + 20*x^4/4! + 480*x^6/6! + 21200*x^8/8! + 1495040*x^10/10! + 154090560*x^12/12! + 21851648000*x^14/14! +...+ A274738(n)*x^(2*n)/(2*n)! +... Compare to the logarithm of A(x), an odd function which begins: log(A(x)) = x + 2*x^3/3! + 20*x^5/5! + 480*x^7/7! + 21200*x^9/9! + 1495040*x^11/11! + 154090560*x^13/13! +...+ A274738(n)*x^(2*n+1)/(2*n+1)! +... thus 1/A(-x) = A(x). PROG (PARI) {a(n) = my(A=1); for(i=0, n, A = 1 + intformal( A^(1+x) +x*O(x^n) ) ); n!*polcoeff(A, n)} for(n=0, 30, print1(a(n), ", ")) (PARI) {a(n) = my(A=1); for(i=0, n, A = exp( intformal( A^x +x*O(x^n) ) ) ); n!*polcoeff(A, n)} for(n=0, 30, print1(a(n), ", ")) CROSSREFS Cf. A274738 (A(x)^x). Sequence in context: A346037 A320918 A325289 * A012246 A012099 A159039 Adjacent sequences:  A274736 A274737 A274738 * A274740 A274741 A274742 KEYWORD nonn AUTHOR Paul D. Hanna, Jul 05 2016 STATUS approved

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Last modified December 4 13:16 EST 2021. Contains 349526 sequences. (Running on oeis4.)