A074250 - OEIS

This site is supported by donations to The OEIS Foundation.

A074250

Smallest p>1 for which n^p ends with n, or -1 if no such p exists. The smallest p for which n is a p-morphic number.

2, 5, 5, 3, 2, 2, 5, 5, 3, -1, 11, 21, 21, -1, -1, 6, 21, -1, 11, -1, 6, -1, 21, 3, 2, -1, 21, 21, 11, -1, 11, 5, 21, -1, -1, 6, 21, -1, 11, -1, 6, -1, 5, 11, -1, -1, 21, 21, 3, -1, 3, 21, 21, -1, -1, 6, 5, -1, 11, -1, 6, -1, 21, 11, -1, -1, 21, 5, 11, -1, 11, 21, 21, -1, 3, 2, 21, -1, 11, -1, 6, -1, 21, 11, -1, -1, 21, 21, 11, -1, 11, 21, 5, -1 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	COMMENTS	`For n < 201, 83 numbers cannot be p-morphic numbers, while 116 numbers can be p-morphic number with smallest p varying from e.g. p(5)=3 to p(103)=101. Smallest power p>1 for which n^p has n somewhere (not necessarily at the end!) in its decimal representation is A045537. If positive, the values of p in A045537 are smaller than p in this sequence.`
	LINKS	`Index entries for sequences related to automorphic numbers`
	EXAMPLE	`a(12)=21 because 12^21 is the smallest power (>1) of 12 which ends by 12 (that is 12 is 21-morphic number), a(14)=-1 because there is no power (>1) of 14 which ends by 14 (that is 14 can not be any p-morphic number).`
	CROSSREFS	`Cf. A045537.` `Sequence in context: A153354 A153821 A153879 * A007292 A161013 A115522` `Adjacent sequences: A074247 A074248 A074249 * A074251 A074252 A074253`
	KEYWORD	`sign`
	AUTHOR	`Zak Seidov (zakseidov(AT)yahoo.com), Sep 20 2002`

Content is available under The OEIS End-User License Agreement .

Last modified February 14 23:16 EST 2012. Contains 205687 sequences.