A078278
a(n) is the number from which if odd-positioned digits are deleted then one gets the concatenation of first n prime numbers, while if even-positioned digits are deleted then one gets reverse concatenation of first n prime numbers. Position of least significant digit is considered to be 1.
Original entry on oeis.org
22, 2332, 253352, 27355372, 213157751312, 2133517117151332, 21375173111117351372, 213951771113113117751392, 2233517911171133117117952332, 22395273111911371173119127352392
Offset: 1
a(4) = 27355372: deleting alternate digits starting from the LSD leaves 2357. Deleting the other ones leaves 7532.
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 19 2003
A078279
a(n) is the number from which if odd-positioned digits are deleted then one gets the concatenation of first n composite numbers, while if even-positioned digits are deleted then one gets reverse concatenation of first n composite numbers. Position of least significant digit is considered to be 1.
Original entry on oeis.org
44, 4664, 486684, 49688694, 416089981604, 4162819019081624, 41648192110019281644, 416581941102112019481654, 4166819511041122114019581664, 41688196110511241142115019681684
Offset: 1
a(4) = 49688694: deleting alternate digits starting from the LSD leaves 4689. Deleting the other ones leaves 9864.
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 19 2003
Original entry on oeis.org
1, 106, 11516, 1243426, 9688988696, 96978050779606, 971598777778061426, 9725080505141505352336, 101523541416869687141725106, 1017966959632335053323596697836
Offset: 1
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