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 A186194 A002275(n) * (A002275(n)+1). 0
 0, 2, 132, 12432, 1235432, 123465432, 12345765432, 1234568765432, 123456798765432, 12345679098765432, 1234567902098765432, 123456790132098765432, 12345679012432098765432, 1234567901235432098765432, 123456790123465432098765432 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS a(1),a(2),a(3),a(4),a(5) are (between the two 0's) the cores of the decimal expansions of a(10),a(11),a(12),a(13),a(14). First differences begin 130,12300,1223000,122230000,.... LINKS Index entries for linear recurrences with constant coefficients, signature (111,-1110,1000). FORMULA a(n)=2*A003555(n+1). n 1's followed by n 8's is b(n)=18,1188,111888,11118888,1111188888, ...; then a(n)=b(n)/9. See its "contrary" A184337(n+1). G.f. 2*x*(-1+45*x) / ( (x-1)*(100*x-1)*(10*x-1) ). - R. J. Mathar, Mar 10 2011 EXAMPLE a(1)=1*2=2, a(2)=11*12=132, a(3)=111*112=12432. CROSSREFS Sequence in context: A020524 A157071 A174585 * A099682 A214436 A135759 Adjacent sequences:  A186191 A186192 A186193 * A186195 A186196 A186197 KEYWORD nonn,easy AUTHOR Paul Curtz, Feb 14 2011 EXTENSIONS Zero added by Franklin T. Adams-Watters, Mar 09 2011 STATUS approved

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Last modified April 15 01:24 EDT 2021. Contains 342974 sequences. (Running on oeis4.)