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%I #16 May 10 2014 09:51:34
%S 2401,279841,15752961,20151121,35153041,43046721,62742241,68574961,
%T 88529281,200533921,260144641,547981281,671898241,2385443281,
%U 2655237841,2750058481,2847396321,3262808641,3722098081,4640470641,5887339441,6414247921,8428892481,8882874001
%N Fourth powers that become prime when their most significant (leftmost) decimal digit is removed.
%C This is to fourth powers A000583 as A226090 is to as cubes A000578, and as A225873 is to squares A000290.
%e a(1) = 7^4 = 2401, because removing the leftmost digit (4) leaves 401, which is prime.
%e a(2) = 23^4 = 279841, because removing the leftmost digit (2) leaves 79841, which is prime.
%e a(3) = 63^4 = 15752961, because removing the leftmost digit (1) leaves 5752961, which is prime.
%e a(10) = 119^4 = 200533921, because removing the leftmost digit (2) leaves 00533921 = 533921, which is prime.
%t Select[Range[307]^4, PrimeQ@Mod[#, 10^IntegerLength@#/10] &] (* _Giovanni Resta_, May 26 2013 *)
%Y Cf. A000583, A225873, A226090.
%K nonn,base,easy
%O 1,1
%A _Jonathan Vos Post_, May 26 2013
%E a(13)-a(24) from _Giovanni Resta_, May 26 2013