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 A077695 a(n) = triangular number pertaining to the number f(n) obtained by concatenating n n times. 1
 1, 253, 55611, 9876790, 1543206790, 222222111111, 30246911419753, 3950617249382716, 499999999500000000, 51015202530354045509590858075706560555, 617283950617283950617716049382716049382716 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) = triangular number corresponding to A000461(n). LINKS Harvey P. Dale, Table of n, a(n) for n = 1..166 EXAMPLE a(4) = 9876790 = 4444*4445/2. MATHEMATICA (#(#+1))/2&/@Table[FromDigits[Flatten[IntegerDigits/@PadRight[{}, n, n]]], {n, 15}] (* Harvey P. Dale, Oct 15 2021 *) CROSSREFS Cf. A077692, A077693, A077694, A000461. Sequence in context: A255182 A176087 A006060 * A253880 A145628 A237419 Adjacent sequences:  A077692 A077693 A077694 * A077696 A077697 A077698 KEYWORD base,nonn AUTHOR Amarnath Murthy, Nov 18 2002 EXTENSIONS More terms from Sascha Kurz, Jan 07 2003 STATUS approved

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Last modified January 24 00:05 EST 2022. Contains 350515 sequences. (Running on oeis4.)