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A370610
Squares such that any two consecutive decimal digits differ by 1 after arranging the digits in decreasing order.
4
0, 1, 4, 9, 324, 576, 4356, 5476, 23104, 32041, 13527684, 13675204, 17430625, 21307456, 34857216, 35617024, 43507216, 56731024, 65318724, 73256481, 81432576, 102576384, 105637284, 139854276, 152843769, 157326849, 158306724, 176305284, 180472356, 183467025, 187635204
OFFSET
1,3
COMMENTS
Squares in A215014. There are 160 terms in this sequence.
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..160
PROG
(PARI) isconsecutive(m, {b=10})=my(v=vecsort(digits(m, b))); for(i=2, #v, if(v[i]!=1+v[i-1], return(0))); 1 \\ isconsecutive(k, b) == 1 if and only if any two consecutive digits of the base-n expansion of m differ by 1 after arranging the digits in decreasing order
a(n) = issquare(n) && isconsecutive(n)
(Python)
from math import isqrt
from sympy.ntheory import digits
def afull(): return([i*i for i in range(isqrt(10**10)+1) if len(d:=sorted(str(i*i))) == ord(d[-1])-ord(d[0])+1 == len(set(d))])
print(afull()) # Michael S. Branicky, Feb 23 2024
CROSSREFS
Cf. A215014, A370370. Supersequence of A036745.
The square roots are given by A370362.
Sequence in context: A029734 A085065 A068708 * A367451 A063248 A027522
KEYWORD
nonn,base,fini,full
AUTHOR
Jianing Song, Feb 23 2024
STATUS
approved