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A264804
a(n) is least number > 0 such that the concatenation of a(1) ... a(n) is 11-gonal: (9n^2 - 7n)/2.
6
1, 1, 526, 64095, 21420730041, 4528059468080555555556, 3834345160635370971474665069772601398563211, 100751687713984558500838936986634939491022212000570658953744730444103042117925197608458
OFFSET
1,3
LINKS
PROG
(PARI) hendecagonal(n)=ispolygonal(n, 11)
first(m)=my(v=vector(m), s=""); s="1"; print1(1, ", "); for(i=2, m, n=1; while(!hendecagonal(eval(concat(s, Str(n)))), n++); print1(n, ", "); s=concat(s, Str(n)))
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Anders Hellström, Nov 25 2015
EXTENSIONS
a(5)-a(8) from Chai Wah Wu, Mar 16 2018
STATUS
approved